Silicon Schottky Barrier Detector Diodes [Alpha CDB, DDB Series Features @ Low 1/f Noise Bonded Junctions for Reliability @ Planar Passivated Beam-Lead and Chip Construction Description Alpha packaged, beam-lead and chip Schottky barrier detector diodes are designed for applications through 40 GHz in Ka-band. They are made by the deposition of a suitable barrier metal on an epitaxial silicon substrate to form the junction. The process and choice of materials result in low series resistance along with a narrow spread of capacitance values for close impedance control. P-type silicon is used to obtain superior 1/f noise characteristics. The packaged diodes are suitable for use in waveguide, coaxial, and stripline applications. Applications These diodes are categorized by TSS (Tangential Signal Sensitivity) for detector applications in four frequency ranges: S, X, Ku, and Ka-band. However, they can also be used as modulators, high speed switches and low power limiters. RF parameters on chips and beamlead diodes are tested on a sample basis, while breakdown voltage and capacitance measurements are 100% tested. Packaged diodes are 100% RF tested. The beamlead and chip diodes can also be mounted in a variety of packages or on special customer substrates. Unmounted beam~lead diodes are especially well suited for use in MIC applications. | Mounted beam-lead diodes can be easily used in MIC, stripline or 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 one parameter that best describes a diode's 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. ALPHA INDUSTRIES, INC. 20 SYLVAN ROAD, WOBURN, MA 01801 TEL: (617) 935-5150 * FAX: (617) 824-4579The Schottky barrier diodes in this data sheet are of P-type construction and are optimized for low noise, particularly in the 1/f region. They require a small forward bias (to overcome the barrier potential) if efficient operation is required, especially at power levels below -20 dBm. Bias not only increases sensitivity but also greatly reduces parameter variation due to temperature change. Video impedance is a direct function of bias and closely follows the 28/Il (mA) relationship. This is important _ Silicon Schottky Barrier Detector Diodes CDB, DDB Series to pulse fidelity, since the video impedance in conjunction with the detector output capacitance affects the effective amplifier bandwidth. Bias does, however, increase noise, particularly in the 1/f region. Therefore, it should be kept at as low a level as possible (typically 5-50 microamps). Voltage output versus power input as a function of load resistance and bias is shown in Figures 1a and 1b. Electrical Specifications Packaged Low 1/f Noise (6.0 dB Max) Electrical Characteristics Test Conditions TSS - 2 Cc ov : Frequency Part dBm"? (oma) pF Frequency Drawing Band Number min min max max GHz Holder Number C-X DDB4517-006 50 500 700 - 5,11 P066 207-001 C-X DDL6672-006 48 500 700 - 5, 11 P-085 075-0014 C-X DDB4517-000 47 500 700 - 5,11 P066 207-001 Cc-X DDL6672-000 45 500 700 - 5,11 P085 075-0014 xX DDL6725-000 48 500 700 - 10.525 Optimized 005-801 K DDB6673-094 50 - - 0.10 24.15 Optimized 207-001 KA DD8B6673-000 40 500 700 - 34.86 P-064 207-001 Beam-Lead Low 1/f Noise (6.0 dB Max) xX DDB4719-000 50 500 700 0.15 10 - 130-011 X DDB2503-000 50 500 700 0.15 10 - 491-006 Xx DDB3321-000 50 500 700 0.15 10 ~ 295-011 xX DDB3268-000 50 500 700 0.15 10 - 364-011 Ku DDB3263-000 48 500 700 0.10 16 - 130-011 Ku DDB2504-000 48 500 700 0.10 16 - 491-006 Ku DDB3266-000 49 500 700 0.10 16 - 295-011 Ku DDB4393-000 49 500 700 0.10 16 ~ 364-011 K DDB5098-000 503 8008 1200 0.10 24.15 - 130-011 K DDB2265-000 50 8003 1200 0.10 24.15 - 491-006 K DDB3267-000 503 8007 | 12003 0.10 24.15 - 295-011 K DDB3269-000 503 8008 1200 0.10 24.15 ~ 364-011 Chip Low 1/f Noise (6.0 dB Max) X/Ku CDB7620-000 50 500 700 0.15 18 - 526-006 Ku/K CDB7619-000 48 500 700 0.10 20 - 526-006 1. Bias =50 pA. 2. Video Bandwidth = 10 MHz. 3. Bias = 30 pA. 4. For stripline applications, ali diodes in the 075-001 package are available with flattened leads. Maximum operating temperature =150C. ALPHA INDUSTRIES, INC. 20 SYLVAN ROAD, WOBURN, MA 01801 TEL: (617) 935-5150 * FAX: (617} 824-4579Silicon Schottky Barrier Detector Diodes CDB, DDB Series Typical Performance Data 12 a) Biased Ru = 10K a) Unbiased \ 10000.00 \ a Bypass | RL = 1MQ -, Input. . NM] __ . Video Output 1000.00L Set > CLA Ry =1ka lL] : ~ } a Load Resistor >< IZ, L oe DC Return = E 100.00. L L L 3 | Y Vf AL = 102 = = LZ 4 Z Bias Supply > Y 2 $ 10.00 7 7 // Vl fA 1.00 A / f RF Bypass / / / / / Test Conditions: Input | Video Output F=9.375 GHz 9 / DC Bias : 0 0.10 f 7 Load Resistor DC Return = boii T T T T T 10 20 } ow So | rm oO | = oO oO Power input, dBm . Multi OctaveHigh Sensitivity Figure 1a. Voltage Output vs. Power Input as a Function of Load Resistance poi iisit Bias Supply Y LK ow a) Biased Vl RF Bypass 7 Input . Mon Output a 10.00 a) Unbiased RF Bypass 10000.003 A= iM@ Input, NJ yp Video Output q * ? O J A Le" Ri = 1KQ ! | 4000.00; FA Load Resistor 3 so uA YO wa 50Q OO La | 100.00 I! A = = Jo Pot i Voltage Output, mV 1.00 | fy 5 yA M- Test Conditions: F=9.375 GHz 0.10 /: S08 = Load Resistor . ' Tot DC Return = bot ii -30 -20 -10 0 10 20 Power Input, dBm BroadbandLow Sensitivi Figure 1b. Voltage Output vs. Power Input as a v Function of Load Resistance and Bias Figure 2. Typical Video Detector Circuits Frequency Table Band Frequencies (GHz) UHF Up to 1 L 1-2 S 2-4 Cc 4-8 x 8.2-12.4 Ku 12.4-18 K 18.0 26.5 Ka 26.5 40 mm 40-100 ALPHA INDUSTRIES, INC. 20 SYLVAN ROAD, WOBURN, MA 01801 5-38 TEL: (617) 935-5150 * FAX: (617) 824-4579