Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Hybrid Coupler
3 dB, 90
°
Description
The XC3500P-03S is a low profile, high performance 3dB hybrid coupler in
a new easy to use, manufacturing friendly surface mount package. The
XC3500P-03S is designed particularly for balanced power and low noise
a
mplifiers, plus signal distribution and other applications where low
insertion loss and tight amplitude and phase balance is required. It can be
used in high power applications up to 55 watts.
Parts have been subjected to rigorous qualification testing and they are
manufactured using materials with coefficients of thermal expansion (CTE)
compatible with common substrates such as FR4, G-10, RF-35, RO4003
and polyimide. Produced with 6 of 6 RoHS compliant tin immersion.
Electrical Specifications **
Features:
• 3300 – 3850 MHz
• High Power
• Very Low Loss
• Tight Amplitude Balance
• High Isolation
• Production Friendly
• Tape and Reel
Lead-Free
Frequency Isolation
Insertion
Loss
VSWR
MHz
dB Min
dB Max
Max : 1
3300-3850
21
0.25
1.22
Amplitude
Balance Phase Power Operating
Temp.
dB Max Degrees
Avg. CW Watts
@85
o
C
ºC
± 0.25
90 ± 3.0
55
-55 to +150
Mechanical Outline
.250
±.010
[6.35
±0.25
]
.200
±.010
[5.08
±0.25
]
Pin 4
Pin 1 Pin 2
Pin 3
Pin 4
Pin 3
Pin 2
4X .020
±.004
[0.51
±0.10
]
GND
4X .034
±.004
SQ
[0.86
±0.10
]
Orientation
Marker Denotes
Pin 1
.170
±.004
[4.32
±0.10
]
.120
±.004
[3.05
±0.10
]
Denotes
Array Number
.073
±.015
[1.85
±0.37
]
4X .020
±.004
[0.51
±0.10
]
Pin 1
GND
Dimensions are in Inches [Millimeters]
XC3500P-03S Mechanical Outline
Tolerances are Non-Cumulative
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Hybrid Coupler Pin Configuration
The XC3500P-03S has an orientation marker to denote Pin 1. Once port one has been identified the other ports are
known automatically. Please see the chart below for clarification:
Configuration
Pin 1
Pin 2
Pin 3
Pin 4
Splitter
Input
Isolated
-3dB
90−∠
θ
-3dB
θ
∠
Splitter
Isolated
Input
-3dB
θ
∠
-3dB
90−∠
θ
Splitter
-3dB
90−
∠
θ
-3dB
θ
∠
Input
Isolated
Splitter
-3dB
θ
∠
-3dB
90−∠
θ
Isolated
Input
*Combiner
A
90−∠
θ
A
θ
∠
Isolated
Output
*Combiner
A
θ
∠
A
90−∠
θ
Output
Isolated
*Combiner
Isolated
Output
A
90−∠
θ
A
θ
∠
*Combiner
Output
Isolated
A
θ
∠
A
90−∠
θ
*Note: “A” is the amplitude of the applied signals. When two quadrature signals with equal amplitudes are
applied to the coupler as described in the table, they will combine at the output port. If the amplitudes are
not equal, some of the applied energy will be directed to the isolated port.
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Insertion Loss and Power Derating Curves
Insertion Loss Derating:
The insertion loss, at a given frequency, of a group of
couplers is measured at 25°
C and then averaged. The
measurements are performed under small signal conditions
(i.e. using a Vector Network Analyzer).
The process is
repeated at -55°C, 95°C and 150°C. A best-fit line for the
measured data is computed and then plotted from -55°C to
150°C.
Power Derating:
The power handling and corresponding power derating
plots are a function of the thermal resistance, mounting
surface temperature (base plate temperature), maximum
continuous operating temperature of the coupler, and
the thermal insertion loss. The thermal insertion loss is
defined in the Power Handling section of the data sheet.
As the mounting interface temperature approaches the
maximum continuous operating temperature, the power
handling decreases to zero.
If mounting temperature is greater than 85°
C, Xinger
coupler will perform reliably as long as the input power is
derated to the curve above.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Typical Performance (-55°C, 25°C and 85°C): 3100-4000 MHz
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-50
-40
-30
-20
-10
0
Frequency (MHz)
Return Loss (dB)
Return Loss for XC3500P-03 (Feeding Port 1)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-50
-40
-30
-20
-10
0
Frequency (MHz)
Return Loss (dB)
Return Loss for XC3500P-03 (Feeding Port 2)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-50
-40
-30
-20
-10
0
Frequency (MHz)
Return Loss (dB)
Return Loss for XC3500P-03 (Feeding Port 3)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-50
-40
-30
-20
-10
0
Frequency (MHz)
Return Loss (dB)
Return Loss for XC3500P-03 (Feeding Port 4)
-55ºC
25ºC
85ºC
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Typical Performance (-55°C, 25°C and 85°C): 3100-4000 MHz
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-3.5
-3.4
-3.3
-3.2
-3.1
-3
-2.9
-2.8
-2.7
-2.6
-2.5
Frequency (MHz)
Coupling (dB)
Coupling for XC3500P-03 (Feeding Port 1)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-50
-40
-30
-20
-10
0
Frequency (MHz)
Isolation (dB)
Isolation for XC3500P-03 (Feeding Port 1)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-0.2
-0.175
-0.15
-0.125
-0.1
-0.075
-0.05
-0.025
00
Frequency (MHz)
Insertion Loss (dB)
Insertion Loss for XC3500P-03 (Feeding Port 1)
-55ºC
25ºC
85ºC
3100 3200 3300 3400 3500 3600 3700 3800 3900 4000
-92
-91.5
-91
-90.5
-90
-89.5
-89
-88.5
-88-88
Frequency (MHz)
Phase Balance (deg)
Phase Balance for XC3500P-03 (Feeding Port 1)
-55ºC
25ºC
85ºC
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Definition of Measured Specifications
Parameter
Definition
Mathematical Representation
VSWR
(Voltage Standing Wave Ratio)
The impedance match of
the coupler to a 50Ω
system. A VSWR of 1:1 is
optimal.
VSWR =
min
max
V
V
Vmax = voltage maxima of a standing wave
Vmin = voltage minima of a standing wave
Return Loss
The impedance match of
the coupler to a 50Ω
system. Return Loss is
an alternate means to
express VSWR.
Return Loss (dB)= 20log
1
-
VSWR
1
VSWR +
Insertion Loss
The input power divided
by the sum of the power
at the two output ports.
Insertion Loss(dB)= 10log
direct
cpl
in
PP
P
+
Isolation
The input power divided
by the power at the
isolated port.
Isolation(dB)= 10log
iso
in
P
P
Phase Balance
The difference in phase
angle between the two
output ports.
Phase at coupled port – Phase at direct port
Amplitude Balance
The power at each output
divided by the average
power of the two outputs.
10log
+
2
PP
P
directcpl
cpl
and 10log
+
2
PP
P
directcpl
direct
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Notes on RF Testing and Circuit Layout
The XC3500P-03S Surface Mount Couplers require the use of a test fixture for verification of RF performance. This
test fixture is designed to evaluate the coupler in the same environment that is recommended for installation.
Enclosed inside the test fixture, is a circuit board that is fabricated using the recommended footprint. The part being
tested is placed into the test fixture and pressure is applied to the top of the device using a pneumatic piston. A four
port Vector Network Analyzer is connected to the fixture and is used to measure the S-parameters of the part. Worst
case values for each parameter are found and compared to the specification. These worst case values are reported to
the test equipment operator along with a Pass or Fail flag. See the illustrations below.
Test Board
Test Board
In Fixture
Test Station
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
The effects of the test fixture on the measured data must be minimized in order to accurately determine the
performance of the device under test. If the line impedance is anything other than 50Ω and/or there is a discontinuity
at the microstrip to SMA interface, there will be errors in the data for the device under test. The test environment can
never be “perfect”, but the procedure used to build and evaluate the test boards (outlined below) demonstrates an
attempt to minimize the errors associated with testing these devices. The lower the signal level that is being
measured, the more impact the fixture errors will have on the data. Parameters such as Return Loss and
Isolation/Directivity, which are specified as low as 27dB and typically measure at much lower levels, will present the
greatest measurement challenge.
The test fixture errors introduce an uncertainty to the measured data. Fixture errors can make the performance of the
device under test look better or worse than it actually is. For example, if a device has a known return loss of 30dB and
a discontinuity with a magnitude of –35dB is introduced into the measurement path, the new measured Return Loss
data could read anywhere between –26dB and –37dB. This same discontinuity could introduce an insertion phase
error of up to 1°.
There are different techniques used throughout the industry to minimize the affects of the test fixture on the
measurement data. Anaren uses the following design and de-embedding criteria:
• Test boards have been designed and parameters specified to provide trace impedances of 50
±1Ω. Furthermore, discontinuities at the SMA to microstrip interface are required to be less than
–35dB and insertion phase errors (due to differences in the connector interface discontinuities
and the electrical line length) should be less than ±0.25° from the median value of the four
paths.
• A “Thru” circuit board is built. This is a two port, microstrip board that uses the same SMA to
microstrip interface and has the same total length (insertion phase) as the actual test board. The
“Thru” board must meet the same stringent requirements as the test board. The insertion loss
and insertion phase of the “Thru” board are measured and stored. This data is used to
completely de-embed the device under test from the test fixture. The de-embedded data is
available in S-parameter form on the Anaren website (www.anaren.com).
Note: The S-parameter files that are available on the Anaren.com website include data for frequencies that are
outside of the specified band. It is important to note that the test fixture is designed for optimum performance through
4GHz. Some degradation in the test fixture performance will occur above this frequency and connector interface
discontinuities of –25dB or more can be expected. This larger discontinuity will affect the data at frequencies above
4GHz.
Circuit Board Layout
The dimensions for the Anaren test board are shown below. The test board is printed on Rogers RO4003 material
that is 0.032” thick. Consider the case when a different material is used. First, the pad size must remain the same to
accommodate the part. But, if the material thickness or dielectric constant (or both) changes, the reactance at the
interface to the coupler will also change. Second, the linewidth required for 50Ω will be different and this will introduce
a step in the line at the pad where the coupler interfaces with the printed microstrip trace. Both of these conditions will
affect the performance of the part. To achieve the specified performance, serious attention must be given to the
design and layout of the circuit environment in which this component will be used.
If a different circuit board material is used, an attempt should be made to achieve the same interface pad reactance
that is present on the Anaren RO4003 test board. When thinner circuit board material is used, the ground plane will
be closer to the pad yielding more capacitance for the same size interface pad. The same is true if the dielectric
constant of the circuit board material is higher than is used on the Anaren test board. In both of these cases,
narrowing the line before the interface pad will introduce a series inductance, which, when properly tuned, will
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
compensate for the extra capacitive reactance. If a thicker circuit board or one with a lower dielectric constant is used,
the interface pad will have less capacitive reactance than the Anaren test board. In this case, a wider section of line
before the interface pad (or a larger interface pad) will introduce a shunt capacitance and when properly tuned will
match the performance of the Anaren test board.
Test Board
Testing Sample Parts Supplied on Anaren Test Boards
If you have received a coupler installed on an Anaren produced microstrip test board, please remember to remove the
loss of the test board from the measured data. The loss is small enough that it is not of concern for Return Loss and
Isolation/Directivity, but it should certainly be considered when measuring coupling and calculating the insertion loss
of the coupler. An S-parameter file for a “Thru” board (see description of “Thru” board above) will be supplied upon
request. As a first order approximation, one should consider the following loss estimates:
Frequency Band
Avg. Ins. Loss of Test Board @ 25°C
410 – 500 MHz
~ 0.03dB
800 – 1000 MHz
~0.06dB
1700 – 2300 MHz
~0.15dB
2300 – 2700 MHz
~0.16dB
3300 – 3800 MHz
~0.19dB
For example, a 1900MHz, 10dB coupler on a test board may measure –10.30dB from input to the coupled port at
some frequency, F1. When the loss of the test board is removed, the coupling at F1 becomes -10.18dB (-10.30dB +
0.12dB). This compensation must be made to both the coupled and direct path measurements when calculating
insertion loss.
The loss estimates in the table above come from room temperature measurements. It is important to note that the
loss of the test board will change with temperature. This fact must be considered if the coupler is to be evaluated at
other temperatures.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Peak Power Handling
High-Pot testing of these couplers during the qualification procedure resulted in a minimum breakdown voltage of
0.82KV (minimum recorded value). This voltage level corresponds to a breakdown resistance capable of handling at
least 12dB peaks over average power levels, for very short durations. The breakdown location consistently occurred
across the air interface at the coupler contact pads (see illustration below). The breakdown levels at these points will
be affected by any contamination in the gap area around these pads. These areas must be kept clean for optimum
performance. It is recommended that the user test for voltage breakdown under the maximum operating conditions
and over worst case modulation induced power peaking. This evaluation should also include extreme environmental
conditions (such as high humidity).
Orientation Marker
A printed circular feature appears on the top surface of the coupler to designate Pin 1. This orientation marker is not
intended to limit the use of the symmetry that these couplers exhibit but rather to facilitate consistent placement of
these parts into the tape and reel package. This ensures that the components are always delivered with the same
orientation. Refer to the table on page 2 of the data sheet for allowable pin configurations.
Test Plan
Xinger II couplers are manufactured in large panels and then separated. A sample population of parts is RF small
signal tested at room temperature in the fixture described above. All parts are DC tested for shorts/opens. (See
“Qualification Flow Chart” section for details on the accelerated life test procedures.)
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Power Handling
The average power handling (total input power) of a Xinger coupler is a function of:
• Internal circuit temperature.
• Unit mounting interface temperature.
• Unit thermal resistance
• Power dissipated within the unit.
All thermal calculations are based on the following assumptions:
• The unit has reached a steady state operating condition.
• Maximum mounting interface temperature is 85oC.
• Conduction Heat Transfer through the mounting interface.
• No Convection Heat Transfer.
• No Radiation Heat Transfer.
• The material properties are constant over the operating temperature range.
Finite element simulations are made for each unit. The simulation results are used to calculate the unit thermal
resistance. The finite element simulation requires the following inputs:
• Unit material stack-up.
• Material properties.
• Circuit geometry.
• Mounting interface temperature.
• Thermal load (dissipated power).
The classical definition for dissipated power is temperature delta (∆T) divided by thermal resistance (R). The
dissipated power (Pdis) can also be calculated as a function of the total input power (Pin) and the thermal insertion loss
(ILtherm):
)(101 10 WP
R
T
P
therm
IL
indis
−⋅=
∆
=
−
(1)
Power flow and nomenclature for an “X” style coupler is shown in Figure 1.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Pin 1
Pin 4
Input Port
Coupled Port Direct Port
Isolated Port
PIn POut(RL) POut(ISO)
POut(CPL) POut(DC)
Figure 1
The coupler is excited at the input port with Pin (watts) of power. Assuming the coupler is not ideal, and that there are
no radiation losses, power will exit the coupler at all four ports. Symbolically written, Pout(RL) is the power that is
returned to the source because of impedance mismatch, Pout(ISO) is the power at the isolated port, Pout(CPL) is the
power at the coupled port, and Pout(DC) is the power at the direct port.
At Anaren, insertion loss is defined as the log of the input power divided by the sum of the power at the coupled and
direct ports:
Note: in this document, insertion loss is taken to be a positive number. In many places, insertion loss is written as a
negative number. Obviously, a mere sign change equates the two quantities.
)dB(
P
P
P
log
10IL
)DC(out
)CPL
(out
in
10
+
⋅=
(2)
In terms of S-parameters, IL can be computed as follows:
)
dB(SSlog10IL
2
41
2
3110
+⋅
−=
(3)
We notice that this insertion loss value includes the power lost because of return loss as well as power lost to the
isolated port.
For thermal calculations, we are only interested in the power lost “inside” the coupler. Since Pout(RL) is lost in the
source termination and Pout(ISO) is lost in an external termination, they are not be included in the insertion loss for
thermal calculations. Therefore, we define a new insertion loss value solely to be used for thermal calculations:
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
)(log10
)()()()(
10
dB
PPPP
P
IL
RLoutISOoutDCoutCPLout
in
therm
+++
⋅=
(4)
In terms of S-parameters, ILtherm can be computed as follows:
)
(log10
2
41
2
31
2
21
2
1110
dBSSSSIL
therm
+++⋅−=
(5)
The thermal resistance and power dissipated within the unit are then used to calculate the average total input power
of the unit. The average total steady state input power (Pin) therefore is:
)(
101101
1010
W
R
T
P
P
thermtherm ILIL
dis
in
−
∆
=
−
=
−−
(6)
Where the temperature delta is the circuit temperature (Tcirc) minus the mounting interface temperature (Tmnt):
)( CT
TT o
mnt
circ −=∆
(7)
The maximum allowable circuit temperature is defined by the properties of the materials used to construct the unit.
Multiple material combinations and bonding techniques are used within the Xinger II product family to optimize RF
performance. Consequently the maximum allowable circuit temperature varies. Please note that the circuit
temperature is not a function of the Xinger case (top surface) temperature. Therefore, the case temperature cannot
be used as a boundary condition for power handling calculations.
Due to the numerous board materials and mounting configurations used in specific customer configurations, it is the
end users responsibility to ensure that the Xinger II coupler mounting interface temperature is maintained within the
limits defined on the power derating plots for the required average power handling. Additionally appropriate solder
composition is required to prevent reflow or fatigue failure at the RF ports. Finally, reliability is improved when the
mounting interface and RF port temperatures are kept to a minimum.
The power-derating curve illustrates how changes in the mounting interface temperature result in converse changes
of the power handling of the coupler.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Mounting
In order for Xinger surface mount couplers to work
optimally, there must be 50Ω transmission lines leading
to and from all of the RF ports. Also, there must be a
very good ground plane underneath the part to ensure
proper electrical performance. If either of these two
conditions is not satisfied, electrical performance may not
meet published specifications.
Overall
ground is improved if a dense population of
plated through holes connect the top and bottom ground
layers of the PCB. This minimizes ground inductance
and improves ground continuity. All of the Xinger hybrid
and directional couplers are constructed from ceramic
filled PTFE composites which possess excellent electrical
and mechanical stability.
When a surface mount hybrid coupler is mounted to a
printed circuit board, the primary concerns are; ensuring
the RF pads of the device are in contact with the circuit
trace of the PCB and insuring the ground plane of neither
the component nor the PCB is in contact with the RF
signal.
Mounting Footprint
4X .034
[0.86]
.170
[4.32]
.120
[3.05]
4X 50
Transmission
Line
Multiple
plated thru holes
to ground
Dimensions are in Inches [Millimeters]
XC3500P-03S Mechanical Outline
To ensure proper electrical and thermal performance
there must be a ground plane with 100% solder
connection underneath the part orientated as shown
with text facing up.
Coupler Mounting Process
The process for assembling this component is a
conventional surface mount process as shown in Figure
1. This process is conducive to both low and high volume
usage.
Figure 1: Surface Mounting Process Steps
Storage of Components:
The Xinger II products are
available in an immersion tin finish. Commonly used
storage procedures used to control oxidation should be
followed for these surface mount components. The
storage temperatures should be held between 15OC and
60OC.
Substrate:
Depending upon the particular component,
the circuit material has a coefficient of thermal expansion
(CTE) similar to commonly used board substrates such
as RF35, RO4003, FR4, polyimide and G-10 materials.
The similarity in CTE minimizes solder joint stresses due
to similar expansion rates between component and
board. Mounting to “hard
” substrates (alumina etc.) is
possible depending upon operational temperature
requirements. The solder surfaces of the coupler are all
copper plated with an immersion tin finish.
Solder Paste: All conventional solder paste formulations
will work well wit
h Anaren’s Xinger II surface mount
components. Solder paste can be applied with stencils or
syringe dispensers. An example of a stenciled solder
paste deposit is shown in Figure 2. As shown in the
figure solder paste is applied to the four RF pads and the
entire ground plane underneath the body of the part.
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Figure 2: Solder Paste Application
Coupler Positioning: The surface mount coupler can
be placed manually or with automatic pick and place
mechanisms. Couplers should be placed (see Figure 3
an
d 4) onto wet paste with common surface mount
techniques and parameters. Pick and place systems
must supply adequate vacuum to hold an
approximately 0.160 gram coupler.
Figure 3: Component Placement
Figure 4: Mounting Features Example
Reflow: The surface mount coupler is conducive to most of
today’s conventional reflow methods. A low and high
temperature thermal reflow profile are shown in Figures 5
and 6, respectively. Manual soldering of these components
can be done with conventional surface mount non-contact
hot air soldering tools. Board pre-
heating is highly
recommended for these selective hot air soldering
methods. Manual soldering with conventional irons should
be avoided.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Figure 5 – Low Temperature Solder Reflow Thermal Profile
Figure 6 – High Temperature Solder Reflow Thermal Profile
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Qualification Flow Chart
Xinger II Product
Qualification
Mechanical/Visual
Inspection
n=50
Electrical Testing at
room temperature
S-parameter n=25
Mount Parts to test
board
n=25
Visual Inspection
n=25
Control Units
n=5
Visual Inspection
n=25
Resistance to Solder Mil 202G,
Method 210F, Condition K Heat
n=25
Visual Inspection
n=25
RF Test @ 25°C
n=25
Visual Inspection
n=25
Electrical Testing at room temperature and over
temperatures (-55°, 25°C & 85°C)
S-parameter
Visual Inspection
n=25
Control Units
n=5
Mechanical/Visual
Inspection n=25
Voltage Breakdown Test Mil
202F, Method 301 25°C 6KVA
n=40
Control Units
n=5
Electrical Testing at room
temperature S-parameter
n=50
Visual Inspection
n=50
Electrical testing at room
temperature S-parameter
n=50
Control Units
n=10
Thermal Cycle 75 cycles -55° to
125°C/min 15 min. dwell n=40
n=50
Visual Inspection
n=50
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Electrical Testing at room
temperature S-parameter
n=50
Electrical Testing at room
temperature S-parameter
n=50
Control Units
n=10
Life Testing
n=6
Control Units
n=10
Visual Inspection
n=50
Moisture Resistance Testing 25° to 65°C for 2 hrs.
@ 90% humidity. Increase to 95% humidity and
soak for 4 hrs. ramp temp to 25°C in 2 hrs., repeat
for 10cycles and then soak -10°C hour 3hrs. n=40
Visual Inspection
n=16
Electrical testing at room temperature
n=6
Visual Inspection
n=25
Microsection 2 Life, 1
high power
and 1 control
Bake parts for 1 hour at
100°C n=40
Electrical Testing at room
temperature S-parameter
n=50
Mechanical
Inspection n=25
Microsection 3 test
units and 1 control
High Power Test
n=2
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Application Information
The XC3500P-03S is an “X” style 3dB (hybrid) coupler. Port configurations are defined in the table on page 2 of this
data sheet and an example driving port 1 is shown below.
Ideal 3dB Coupler Splitter Operation
1
2
1V
0.707V∠θ (-3dB)
0.707V ∠θ -90 (-3dB)
Isolated Port
4
3
The hybrid coupler can also be used to combine two signals that are applied with equal amplitudes and phase
quadrature (90º phase difference). An example of this function is illustrated below.
Ideal 3dB Coupler Combiner Operation
1
2
1V∠Φ
0.707V∠θ
0.707V ∠θ -90
Isolated Port
4
3
3dB couplers have applications in circuits which require splitting an applied signal into 2, 4, 8 and higher binary
outputs. The couplers can also be used to combine multiple signals (inputs) at one output port. Some splitting and
combining schemes are illustrated below:
2-Way Splitter/Combiner Network
Amplitude and
Phase tracking
Devices
* 50Ω
Termination
* 50Ω
Termination
Output
Input
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
4-Way Splitter/Combiner Network
Output
* 50Ω
Termination
* 50Ω
Termination
Input
Amplitude and
Phase tracking
Devices
Amplitude and
Phase tracking
Devices
* 50Ω
Termination
* 50Ω
Termination
* 50Ω
Term.
* 50Ω
Term.
The splitter/combiner networks illustrated above use only 3dB (hybrid) couplers and are limited to binary divisions (2
n
number of splits, where n is an integer). Splitter/combiner circuits configured this way are known as “corporate”
networks. When a non-binary number of divisions is required, a “serial” network must be used. Serial networks can be
designed with [3, 4, 5, ….., n] splits, but have a practical limitation of about 8 splits.
A 5dB coupler is used in conjunction with a 3dB coupler to build 3-way splitter/combiner networks. An ideal version of
this network is illustrated below. Note what is required; a 50% split (i.e. 3dB coupler) and a 66% and 33% split (which is
actually a 4.77dB coupler, but due to losses in the system, higher coupler values, such as 5dB, are actually better
suited for this function). The design of this type of circuit requires special attention to the losses and phase lengths of
the components and the interconnecting lines. A more in depth look at serial networks can be found in the article
“Designing In-Line Divider/Combiner Networks” by Samir Tozin, which describes the circuit design in detail and can be
found in the White Papers Section of the Anaren website, www.anaren.com.
3-Way Splitter/Combiner
1/3 Pin
2/3 Pin
1/3 Pin
1/3 Pin
G=1
G=1
G=1
Pout
2/3 Pin
Pin
1/3 Pin
1/3 Pin
1/3 Pin
5 dB (4.77)
coupler
3 dB coupler
3 dB coupler
5 dB (4.77)
coupler
* 50Ω
Termination
* 50Ω
Termination
* 50Ω
Termination
* 50Ω
Termination
*Recommended Terminations
Power (Watts)
Model
8
RFP-060120A15Z50
15
RFP-250375A4Z50
50
RFP-375375A6Z50
100
RFP-500500A6Z50
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Reflections From Equal Unmatched Terminations
Referring to the illustration below, consider the following reflection properties of the 3dB coupler. A signal applied to
port 1 is split and appears at the two output ports, ports 3 & 4, with equal amplitude and in phase quadrature. If ports
3 & 4 are not perfectly matched to 50Ω there will be some signal reflected back into the coupler. If the magnitude and
angle of these reflections are equal, there will be two signals that are equal in amplitude and in phase quadrature (i.e.
the reflected signals) being applied to ports 3 & 4 as inputs. These reflected signals will combine at the isolated port
and will cancel at the input port. So, terminations with the same mismatch placed at the outputs of the 3dB coupler will
not reflect back to the input port and therefore will not affect input return loss.
Γ=
0
0
Z
Z
ZZ
L
L
+
−
1
2
1V
0.707V∠θ (-3dB)
0.707V ∠θ -90 (-3dB)
Isolated Port
4
3
Termination = ZL
Γ× 0.707V ∠θ -90
Γ× 0.707V ∠θ
|Γ (0.5V ∠2θ -90 + 0.5V ∠2θ -90)| = |Γ|
Γ (0.5V ∠2θ + 0.5V ∠2θ -180) = 0V
Termination = ZL
The reflection property of common mismatches in 3dB couplers is very beneficial to the operation of many networks.
For instance, when splitter/combiner networks are employed to increase output power by paralleling transistors with
similar reflection coefficients, input return loss is not degraded by the match of the transistor circuit. The reflections
from the transistor circuits are directed away from the input to the termination at the isolated port of the coupler.
This example is not limited to Power Amplifiers. In the case of Low Noise Amplifiers (LNA’s), the reflection property of
3dB couplers is again beneficial. The transistor devices used in LNA’s will present different reflection coefficients
depending on the bias level. The bias level that yields the best noise performance does not also provide the best
match to 50 Ω. A circuit that is optimized for both noise performance and return loss can be achieved by combining
two matched LNA transistor devices using 3dB couplers. The devices can be biased for the best noise performance
and the reflection property of the couplers will provide a good match as described above. An example of this circuit is
illustrated below:
LNA Circuit Leveraging the Reflection Property of 3dB Couplers
Amplitude and phase tracking
LNA devices biased for
optimum noise performance
50Ω
Termination
50Ω
Termination
Output
Input
Energy reflected from LNA
devices biased for optimum
noise performance
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Signal Control Circuits Utilizing 3dB Couplers
Variable attenuators and phase shifter are two examples of signal control circuits that can be built using 3dB couplers.
Both of these circuits also use the reflection property of the 3dB coupler as described above. In the variable attenuator
circuit, the two output ports of a 3dB coupler are terminated with PIN diodes, which are basically a voltage variable
resistor at RF frequencies (consult the literature on PIN diodes for a more complete equivalent circuit). By changing the
resistance at the output ports of the 3dB coupler, the reflection coefficient, Γ, will also change and different amounts of
energy will be reflected to the isolated port (note that the resistances must change together so that Γ is the same for
both output ports). A signal applied to the input of the 3dB coupler will appear at the isolated port and the amplitude of
this signal will be a function of the resistance at the output ports. This circuit is illustrated below:
Variable Attenuator Circuit Utilizing a 3dB Coupler
Vdc
1
2
Input
0.707V∠θ (-3dB)
0.707V ∠θ -90 (-3dB)
Output
4
3
Γ× 0.707V ∠θ -90
Γ× 0.707V ∠θ
|Γ (0.5V ∠2θ -90 + 0.5V ∠2θ -90)| = |Γ|
and
|Output| = | Γ|×|Input|
PIN Diodes
If Γ=0, no energy is reflected from the PIN diodes and S21 = 0 (input to output). If | Γ | =1, all of the energy is reflected
from the PIN diodes and |S21| = 1 (assuming the ideal case of no loss). The ideal range for Γ is –1 to 0 or 0 to 1, which
translate to resistances of 0Ω to 50Ω and 50Ω to ∞Ω respectively. Either range can be selected, although normally 0Ω
to 50Ω is easier to achieve in practice and produces better results. Many papers have been written on this circuit and
should be consulted for the details of design and operation.
Another very similar circuit is a Variable Phase Shifter (illustrated below). The same theory is applied but instead of PIN
diodes (variable RF resistance), the coupler outputs are terminated with varactors. The ideal varactor is a variable
capacitor with the capacitance value changing as a function of the DC bias. Ideally, the magnitude of the reflection
coefficient is 1 for these devices at all bias levels. However, the angle of the reflected signal does change as the
capacitance changes with bias level. So, ideally all of the energy applied to port 1, in the circuit illustrated below, will be
reflected at the varactors and will sum at port 2 (the isolated port of the coupler). However, the phase angle of the signal
will be variable with the DC bias level. In practice, neither the varactors nor the coupler are ideal and both will have
some losses. Again, many papers have been written on this circuit and should be consulted for the details of design and
operation.
Available on Tape
and Reel for Pick and
Place Manufacturing.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Model XC3500P-03S
Rev D
Variable Phase Shifter Circuit Utilizing a 3dB Coupler
Γ× 0.707V ∠θ -90
Vdc
1
2
Input
0.707V∠θ (-3dB)
0.707V ∠θ -90 (-3dB)
Output
4
3
Γ× 0.707V ∠θ
* |Γ (0.5V ∠2θ -90 + 0.5V ∠2θ -90)| =| Γ|
Varactor Diodes
* The phase angle of the signal exiting port 2 will vary with the phase angle of Γ, which is the reflection
angle from the varactor. The varactors must be matched so that their reflection coefficients are equal.
USA/Canada:
Toll Free:
Europe:
Asia:
(315) 233-5510
(833) 389-6402
+44 2392-232392
+86 512 62749282
Available on Tape and
Reel for Pick and Place
Manufacturing.
Model XC3500P-03S
Rev D
Packaging and Ordering Information
Parts are available in both reel and tube. Packaging follows EIA 481-2. Parts are oriented in tape and reel as
shown below. Minimum order quantities are 2000 per reel and 77 per tube. See Model Numbers below for further
ordering information.
Xinger Coupler Frequency (MHz) Size (Inches) Coupling Value Plating Finish
XC
0450 = 410-500
0900 = 800-1000
1900 = 1700-2000
2100 = 2000-2300
2500 = 2300-2500
2650 = 2650-2800
3500 = 3300-3800
A = 0.56 x 0.35
B = 1.0 x 0.50
E = 0.56 x 0.20
L = 0.65 x 0.48
M= 0.40 x 0.20
P = 0.25 x 0.20
03 = 3dB
05 = 5dB
10 = 10dB
20 = 20dB
30 = 30dB
P = Tin Lead
S = Immersion Tin
XX XXXX X - XX X
