ALPHA IND/ SEMICONDUCTOR 48E D MM 05865443 0001309 2Se MALP High Q GaAs Tuning Diodes Features W 50 Percent Higher Q than Comparable Silicon Diodes m@ Wide Tuning Ratio m 25 and 45 Volt Series Types m@ DVE4500 Series m@ DVE6900 Series T0719 Description The Alpha line of gallium arsenide tuning diodes cffers the circuit designer expanded capability. The extremely high Q and superior tuning ratio of these diodes allow tunable oscillators and filters to be built with lower loss and broader bandwidth. The diodes are particularly useful for tuning Gunn and Impatt oscillators. The diode Q is measured in a well-characterized high Q cavity with an unloaded cavity Q of 1500 in the 1 to 2 GHz range. A block diagram of the test set-up is shown in Figure 1. The test cavity is shown in Figure 2. A plot of Q, at 1.0 GHz versus C,, in Figure 3 compares the Alpha gallium arsenide diodes with avail- able silicon diodes. Electrical Characteristics All packaged Aijpha gallium arsenide tuning varac- tors are electrically burned-in prior to final measure- ment. A special variation of this diode family is the only space-qualified, high-reliability varactor available today and is used in the ESRO European satellite program. Absolute Maximum Ratings Parameter Symbol Value Units Reverse Voltage V, | SameasV, | Volts Forward Current |, 40 mAdc Power Dissipation Py 200 mw (T,=25C) Operating Temperature} T,, | -55 to +125 C Storage Temperature Torq | 99 to +175 C DVE4500 Series DVE6900 Series V,'=25 Volts, I, = 50 nanoamps max. V,'=45 Volts, I,= 50 nanoamps max. c,? c as Q, c,? c,! Q! Q, (pF) Ce @ 50 MHz @1 GHz Suffix (pF) Cue @ 50 MHz @1 GHz Suffix 0.4-0.6 1.3 15,000 750 -06 0.4-0.6 2.8 10,000 750 -06 0.6-0.8 1.60 13,000 650 -12 0.6-0.8 2.2 9,000 650 12 0.8-1.0 2.0 12,000 600 -18 0.8-1.0 26 8,000 600 -18 1.0-1.5 2.10 10,000 500 -24 1,0-1.5 2.8 7,000 500 724 1.5-2.0 2.51 7,500 375 -30 1.5-2.0 3.3 6,000 375 -30 2.0-2.5 2.75 6,500 325 -36 2.0-2.5 3.7 5,500 325 -36 2.5-3.0 3.0 5,500 275 -42 2.5-3.0 41 5,000 275 -42 3.0-4.0 3.1 4,300 215 -48 3.0-4.0 42 4,500 215 -48 4.0-5.0 3.3 4,300 215 54 4.0-5.0 43 4,300 215 -54 5.0-6.0 3.3 4,300 215 -60 5.0-6.0 45 4,000 200 -60 Notes: 1. Minimum voltage breakdown is specified at 10 pA. Higher voltage breakdowns are available upon request. 2. Maximum leakage current is specified at 80% of V,,. 3. 10% capacitance tolerance is standard. Specify goal capacitance when ordering. Tighter tolerances are available on request. C. TO 5, Extrapolated down to 50 MHz. is the minimum total capacitance ratio which includes the package capacitance that is normally 0.2 pF. Cre A typical capacitance versus voltage plot appears in Figure 4. 4-11 ALPHA IND/ SEMICONDUCTOR 4OE D MM 0585443 9001310 T?4 MMALP 7-09-/9 High Q GaAs Tuning Diodes Model Number Alpha Model Number Package Style Alpha Model Number Package Style DVE4551 023-001 DVE6951 023-001 DVE4552 168-001 DVE6952 168-001 DVE4575 320-001 DVE6953 320-001 DVE4576 350-001 DVE6954 350-001 DVE4555 290-001 DVE6955 290-001 Note: Add suffixnumber to Alpha Model Number to specify desired electrical characteristics and package style. _- CENERATOR DIRECTIONAL 20d8 CAVITY AND DUT | | AMPLIFIER -26dB osc | COUPLER 5 | ALPHA #13128 [7] 1-2 GHz | DETECTOR | LLOSCOP| 1-2 GHz PAD POWER SUPPLY FOR BIAS Figure 1. Quality Factor Q Test Set-Up ] DEVICE a 4 UNDER TEST ove |p hyo SS QS Figure 2. Test Cavity 4-12 ALPHA IND/ SEMICONDUCTOR UBE D MM 0585443 0001311 900 MBALP 7-07-49 High Q GaAs Tuning Diodes 1000 20,000 900 [_ 18,000 800 16,000 700|__\ DVE4500 SERIES N 114,000 2 N = = 600 po 12,000 Oo = 500, _ Se em 10,000 g 5 GaAs 8,000 CG 400/DVE6900 SERIES G ; a a 300 - p~e{ eo _| 16,000 200 x fa 4,000 SILICON x 100 - {2,000 50 oL_| | | | | | | | | | 7 0.3 04 05 06 0708 09 10 1.1 1.213 14 15 1.61.7 1.8 CT4 Figure3. Q,vs.C,, i a ee rT TTT rT TTTTTS a e212 7 = *s sen vA = ~ S10 o . Leroy a Le Ty _ _ Sac (JUNCTION) 4 CVE 7800 7 4 pot ttt bo te bod at 1 10 100 V+o(V) Figure 4. Typical Capacitance vs. Voltage 4-13