Zero Bias Silicon Schottky Barrier Detector Diodes CDC, DDC Series Features @ High Sensitivity @ Low Video Impedance Description Alphas series of packaged, beam-lead and chip zero bias Schottky barrier detector diodes are designed for applications through K-band. The choice of barrier metal and process techniques results in a diode with a wide selection of video impedance ranges. The packaged diodes are suitable for use in waveguide, coaxial and stripline applications. The beamead and chip diodes can also be mounted in a variety of packages. Applications The zero bias Schottky detector diodes are designed for detector applications through 26 GHz and are useful to 40 GHz. They require no bias and operate efficiently even at tangential signal power levels. Since they require no bias, noise is at a minimum. Their low video impedance means a short R-C time constant and hence wide video bandwidth and excellent pulse fidelity. As power monitors these diodes may also be used to drive metering circuits directly even at low power input levels. These diodes are categorized by TSS (Tangential Signal Sensitivity), voltage output and video impedance for detector applications. Unmounted beam-lead diodes are especially well suited for use in MIC applications. Mounted beam-lead diodes can be easily used in MIC, stripline and other such circuitry. A complete line of chips is shown for those MIC applications where the chip and wire approach is more desirable. TSS is the parameter that best describes a diodes use as a video detector. It is defined as the amount of signal power, below a one milliwatt reference level, required to produce an output pulse whose amplitude is sufficient to raise the noise fluctuations by an amount equal to the average noise level. TSS is approximately 4 dB above the Minimum Detectable Signal. Voltage output is another useful parameter, since it can be used in the design of threshold detectors and power monitor circuits. Since voltage output is a function of the diodes video impedance, a different minimum value is specified for each video impedance range. 3-28 = Alpha Industries [617] 935-5150 Fax [617] 824-4579 E-mail sales@alphaind.com Visit our web sie: www.alphaind.com Zero Bias Silicon Schottky Barrier Detector Diodes Figure 1 is a plot of the forward DC characteristics. In Figure 2 voltage output is plotted as a function of power input for diodes of various video impedances. Tangential Signal Sensitivity as a function of video impedance is shown in Figure 3. Figure 4 shows two typical detector circuits. The Multi OctaveHigh Sensitivity circuit would be used in ECM and similar applications. An RF matching structure that will present the maximum power at the diode junction must be Electrical Specifications at 25C CDC, DDC Series incorporated to insure maximum _ sensitivity. The BroadbandLow Sensitivity circuit would be used where low input VSWR is required. In this circuit the low VSWR is accomplished by the use of the 50 ohm terminating resistor. Sensitivity, however, is degraded by typically 10 dB from the Multi OctaveHigh Sensitivity circuit. The most common use for this circuit is in the broadband, flat detector used primarily in the laboratory. Eo? Vv Tss! Part (mV) (Ohms) dBm Outline Drawing Number Number Min. Min. Max. Min. DDC2353-250 8.0 2000 5000 -52 250 DDC2354-250 15.0 5000 15000 -56 250 DDC2353-240 8.0 2000 5000 -52 240 DDC2354-240 15.0 5000 15000 -56 240 DDC2353-000 8.0 2000 5000 -52 491-006 DDC2354-000 15.0 5000 15000 -56 491-006 CDC7630-000 8.0 2000 5000 -52 526-006 CDC7631-000 15.0 5000 15000 -56 526-006 1. Video bandwidth = 10 MHz. 2 P=-30dBm, R, > 1 MQ, frequency = 9.375 GHz. Alpha Industries [617] 935-5150 Fax [617] 824-4579 E-mail sales@alphaind.com Visit our web site: www.alphaind.com 3-29 Zero Bias Silicon Schottky Barrier Detector Diodes CDC, DDC Series Typical Performance Data Zero Bias Schottky Detector Diodes Typical Zero Bias X-Band Detector Diodes 10.0000 60 1.0000 = < & 58 = Low Video Impedance Types z a = 0.1000 ow ee ypes x SO 5 | Ss 56 B 0.0100 = / Lt a 54 Cc * 9.0010 / A a / V High Video Impedance Types a 52 eee eins ks _| 5 0.0001 [ | | | | | D 0 5 10 15 20 25 30 35 40 50 | 100 1000 10000 100000 Forward Voltage (mV) Video Impedance (Ohms) Figure 1. Typical Forward DC Characteristics . a i. ; Figure 3. Tangential Signal Sensitivity vs. Video Impedance Typical Zero Bias X-Band Detector Diodes . . ad Multi Octave High Sensitivity 10000.003 RF Bypass Video Output 3 LL nput . | : __ . Io leo Outpu 1000.004 5 | Load Resistor 400 ool jj} DC Return > NS E F 7 _ = J Z=10Ko HK. = ao 10.003 A, ~ 5 3 f Oo J Zy =1KQ & 1 4 / Broadband Low Sensitivity 6 4 Ya = 4000. Test Conditions: RF Bypass > 4 Input | | _ Video Output F=9.375 GH e 0101 A R-ioma, 7 lL 0.01 7 50 Q | Load Resistor -50 -40 -30 -20 -10 0 10 20 - i[J-_4 Power Input, dBm Figure 2. Voltage Output vs. Power Input as a Function of Video Impedance Figure 4. Typical Video Detector Circuits 3-30 Alpha Industries [617] 935-5150 Fax [617] 824-4579 E-mail sales@alphaind.com Visit our web site: www.alphaind.com Zero Bias Silicon Schottky Barrier Detector Diodes CDC, DDC Series Typical Performance Characteristics at 9.375 GHz 800 1000.00s 100K cq 5 35 700 100.003 i 10K 5 = 600 = 10.004 io 3 5 5 A 500 = 1.004 A 3 3 q q $ $ 4 J 400 0.104 1K 5 J 300 0.01 ++ T T T -40 -25 -10 5 20 35 50 65 80 95 -30 -20 -10 0 Temperature (C) Pin (dBm) Voltage Output vs Resistance T ' 40. 25, 90C: at 0 dBm vs Temperature C ransfer at 40, 25, RL = 1 Kohm 200 100K, 180 SOK 10003 160 10K J ZO S 140 J E = 120 Ss 1003 we = E 7 LZ 5S 100 q 25 95 $ aC MY 80 | 40 3 104 Z| 60 1K > Yo 40 I -40 -25 -10 5 20 35 50 65 80 95 1 Temperature (C) 30 4-0 10 | 0 ; Pin (dBm) Voltage Output vs Resistance at -10 dBm vs Temperature C Transfer at 40, 25, 90C RL = 100 Kohm 5 100K 4 50K = 3 10K 3 o 3 > 1 1K 0 40 -25 -10 5 20 35 50 65 80 95 Temperature (C) Voltage Output vs Resistance at -30 dBm vs Temperature C Alpha Industries [617] 935-5150 Fax [617] 824-4579 E-mail sales@alphaind.com Visit our web site: www.alphaind.com 93-31 Zero Bias Silicon Schottky Barrier Detector Diodes CDC, DDC Series Outline Drawings 491-006 TOP VIEW SCHEMATIC (0.33 9.013 OBO) Bor; | 9.0660. 15 f9,004 B18 7) _! 2-PLES. 0.28 pm) 0.011 . 9.237 0.009 ) | 4 I i 0.003 (0.23 mmy | 0.007 LG: 33 ma} (0.23 soo | ne a? 0,007 0.0006. CO. 06mm) 0. 0025 0.0902 _f hax. Co.808 DH | 526-006, 526-011 526-006 = Cathode Bond Pad 526-011 = Anode Bond Pad 0.015 (0.38 mm) 0.013 (0.33 mm) 0.015 (0.38 mm) + 0.013 (0.33 mm) Bonding Pad m (526-006 Cathode) 526-011 Anode) Diameter 0.0035 0.0045 0.0085 (0.216 mm ___0.0065 (0.165 mm t 3-32 = Alpha Industries [617] 935-5150 Fax [617] 824-4579 E-mail sales@alphaind.com Visit our web sie: www.alphaind.com