High Cutoff GaAs Parametric Amplifier ALPHA IND/ SEMICONDUCTOR Varactor Diodes WBE D MM 0585443 000138? ?4e MB ALP Features T-07-1| @ Highest Cutoff Frequencies Available, from 900 to 1300 GHz @ More Accurate and Reliable Characterization Description The Alpha DVE6722 and DVE6810 series gallium arsenide parametric amplifier varactor diodes offer the user the highest cutoff frequencies available in the microwave industry today. To obtain the high cutoff frequency and capacitance nonlinearity, a P+ material is diffused into a very thin layer of N type material, witha flat dopling profile, on an N: substrate. Diode frequency cutoff is measured as a function of junction capacitance using the Deloach method. The Deloach measurement technique eliminates holder losses that are present in the conventional Houlding method. With the Deloach method, a direct measure- ment of diode cutoff to low junction capacitance values can be obtained. Burn-in AllGaAs varactors are subjected to burn-in screening priorto final measurements. Typical burn-in for:C,,=0.3 pF is: 60 Hz, |, =30mA. V,=2.5V (50 ohm load) at 100C 16 hours. Measurement Test Circu:t Diagram Reduced Waveguide Cavity Signal Generator pe Attenuator p4 ey Receiver Power F ( Freq #344) fol3) {12(4) Output Signal Notes: 1. Deloach, A New Microwave Measurement Technique to Charac- terize Diodes and an 800 Ge Cutoff Frequency Varactor at Zero Volts Bias. IEEE Transactions on Microwave Theory and Tech- nique, January 1964, pp. 15-20. Signal is applied to diode at series resonance frequency of diode: 1 {= = 2xV LC, T is defined as the insertion loss at resonance in db. Thus, T=10!W10 The loss at f,and f,is 3db less than the insertion loss at resonance. f, f, (-ty V(1-2) This is the cutoff frequency for packaged diode in the Deloach holder. Calculate f,, = 4-89High Cutoff GaAs Parametric Amplifier Varactor Diodes ALPHA IND/ SEMICONDUCTOR General Characteristics (V, min = 10 Volts) WBE D MM 0585443 0001388 689 MBALP 707 //~ Package 290-001 Package 082-001 Cc, t,, , An c. c,4 | f,(6V) Ang Model pt Min. Min. Model pf Min. Min. Number Min. Max. GHz GHz Min. Number Min. Max, GHz GHz Min. DVE6810A 0.35 0.40 360 820 0.555 DVE6722A 0.35 0.40 360 815 0.545 DVE6810B 0.30 0.35 400 900 0.551 OVE6722B 0.30 0.35 400 890 0.541 DVE6810C 0.25 0.30 440 1000 0.547 DVE6722C 0.25 0.30 440 970 0.534 DVE6810D 0.20 0.25 490 1070 0.537 DVE6722D 0.20 0.25 490 1050 0.526 DVE6810E 0.15 0.20 570 1230 0.519 DVE6722E 0.15 0.20 570 1200 0.507 DVE6810F 0.10 0.15 620 1300 0.500 DVE6722F 0.10 0.15 620 1270 0.487 Notes to General Characteristics: 1. Breakdown voltage (B,) is measured at 10 mi- croamps reverse current. 2. Total Capacitance is measured at 1 MHz and 0 bias. Junction Capacitance (C,) is calculated by subtracting the typical package capacitance from the total capaci- tance. Capacitance selection to + 0.025 pF is standard. 3. f,, measured by Deloach method: f, =f, x C,/C, This compares with the Houlding measurement inthe Alpha test fixture for C,, = 0.4 pF and f,, Deloach = 360 GHz while foo Houlding = 270 GHz. Parametric Amplifier Diode Design Choice Parametric amplifier diodes can be chosen for applica- tion using the table below as a guide. The idler frequency is chosen according to the mode of resonance - series or parallel at idler frequency: C,-C 4. AnC,,= C # Log C, vs. log (V + u) gives best fit to straight line for u= 1.2V. 5. Themethodused for calculating junction capacitance includes ribbon stray capacitance as part of C,,. This Stray value is larger for the 082-001 and A nC,, is therefore less than for the 290-001 outline. f idler = f pump - f signal f pump = pump frequency f signal = signal frequency to be amplified Series: Parallel? Resonance Resonance Package C,, Frequency Frequency Product pF GHz GHz Numbers 82 C, = .2 pF 4 15 31 6810A, 4557-01-08 Lp = .2nH 3 21 33 6810B,C 4557-11-26 2 24 36 6810D,E 290 C, =.11 pF 3 21 58 6722B,C 45578-01-08 L, = .10nH 2 24 62 6722D,E 1 32 70 6722F Notes: 1. These values correspond to observed Deloach resonance 1 frequencies. f parallel resonance ~ fo 2. Calculated using equation as follows: nV & Ss0 P C, +C =)