DETECTORS ML 7700-0000 Series DETECTORS 0.1 TO 18.0 GHz FEATURES Schottky & Tunnel Diode Limiter Detectors Broad Frequency Ranges High Sensitivities Coaxial & Drop-in DESCRIPTION The M/A-COM Lid detector range uses both silicon based Schottky barrier diodes and germanium based tunnel diodes. In both types RF detection is achieved through the non-linear, current voltage characteristics of a semiconductor Junction. In Schottky diodes this junction is established between a metal and either p or n type doped silicon and is typically between 0.3V (low barrier) and 0.8V (high barrier) depending on the materials. In tunnel diodes the junction is a pn type formed between two doped semiconductors. When the doping is sufficiently heavy on both sides of the Junction the potential barrier becomes thin enough for electrons to tunnel through the barrier giving rise to a negative resistance. The probability of tunnelling increases as the size of the junction is decreased. Germanium is used as the semiconductor material with a potential barrier of the order of 0.6V. These diode types are selected to offer optimum performance for a wide range of applications. Tunnel diodes offer the best temperature stability, video bandwidth, rise time and wideband RF match. Schottky detectors are chosen for their tugged construction, highest output voltage and best sensitivity. Biased Schottky detectors offer additional advantages by providing higher burnout levels, lower video resistance and improved temperature stability and RF match. These detectors are manufactured using chip diodes, avoiding the performance degrading effects of package parasitics, matched into a hybrid microstrip circuit giving wide frequency band operation. The circuit also incorporates the d.c. return and R.F. bypass elements and where used the PIN diode limiter. The complete assembly is then hermetically sealed into either a coaxial or modular housing. Package styles available include coaxial types with both fixed and removable SMA connectors and module types for both solder and mechanical attachment in stripline and microstrip assemblies. Detectors are also offered in the Common Module (MiCM) format for direct integration with other MiCM components as well as existing microstrip circuits. The package styles are compatible with the MiCM 20 Standard, DEF STAN 59-90 (Part 1) Microwave Common Modules, Part 1: Interfaces and Fixings for use up to 20 GHz and with the Draft CECC 00 017 Issue 1 Basic Specification: Microwave Common Modules for use up to 20 GHz. M/A-COM Lid also offers a custom design capability for detectors with optimised performance and detectors integrated with other circuit functions such as couplers, attenuators and isolators. Please contact the factory for applications assistance. M/A-COM Ltd, Humphrys Road, Dunstable, Bedfordshire, LU5 4SX United Kingdom. Europe: (44) 1344 869595 a North America: 800 366 2266 7 Asia Pacific: (81) 3 3226 1671 385TUNNEL DIODE DETECTORS ML 7700-0000 SERIES DESCRIPTION Tunnel diode detectors generally offer the best temperature stability. The low video resistance of tunnel diodes also provides the widest video bandwidth and fastest rise time. Tunnel diode detectors also offer the best inherent RF match, without special input matching. Open circuit voltage sensitivity and RF power handling are less than the equivalent silicon Schoitky detector but the tunnel detector's low video impedance and zero bias operation enables dc and ac coupling with video and log video amplifiers. This series of detectors provides a usable 67dB dynamic range from nominal T,, of -50dBm to maximum saturation at +17dBm. Within this range square law response is from T,, to -15dBm, linear response from -15dBm to +5dBm and saturation from +5dBm to +17dBm. Above +17dBm diode damage and subsequent burnout occurs. SPECIFICATIONS @ +25c Voltage RF Bypass Video Sensiti- Capacit- Rise Resist Frequency vity (K) VSWR ss Flatness Tss ance Time ~ance Range (mV/mW) = (Ratio) (dB) (dBm) (pF) (ns) (ohms) Part Number (GHz) Min. Max Max Min. Typ. Typ. Typ. 0.1 - 2.0 800 2.0 40.5 -50 100 15 120. =ML7700X-0020 2.0 - 8.0 800 2.0 40.6 -50 20 4 120 ML 7700X-0021 8.0 - 18.0 500 2.3 10 -50 20 4 100 =ML7700X-0022 2.0 - 18.0 500 2.5 415 -50 20 4 100 ML 7700X-0023 NOTES 1. Available package styles for these detectors are A, D, J, Hor M. To specify the package style please replace 'X' with the required letter in the above part numbers, e.g. for a coaxial package detector the part number is ML 7700A-0020. 2. Detectors are normally supplied with negative (-) output voltage polarity, referenced to case ground, positive (+) output polarity is available for most parts. To specify positive output please add suffix 'P' to the end of the part number e.g. ML 7700A-0020P. 3. Minimum open circuit voltage sensitivity (K) is the ratio of output voltage to input RF power and is measured at -20dBm RF input power into 30kohm external video load resistance (R,). 4. VSWR is measured at -20dBm RF input power into 100 ohm external video load resistance (R,). 5. Tangential signal sensitivity (Ts) is defined as the RF input power which produces an 8dB video output to noise voltage ratio and is measured using a video amplifier restricted to 2MHz bandwidth and having a noise contribution of 34B maximum. 6. Pulse rise time (t,) is measured into an external load (R,) of 100 ohms with 12pF in parallel. 7. Video resistance is measured at -20dBm RF input power. 8. Case operating temperature -55C to +95C Storage temperature -55C to +125C. M/A-COM Ltd, Humphrys Road, Dunstable, Bedfordshire, LUS 4SX United Kingdom. Europe: (44) 1344 869595 a North America: 800 366 2266 7 Asia Pacific: (81) 3 3226 1671 386ML 7700-0000 SERIES TYPICAL PERFORMANCE 1400 1000 1200 1000 Q 1K QLOAD 800 1K QLOAD 30K 0 LOAD 100 Mh IDEAL 600 SQUARE LAW 100 2 LOAD R, =30kK Q 400 200 R,=1K 0 R, =100 2 SENSITIVITY (mV/mW @ -20 dBm INPUT 8 FREQUENCY (GHz) = OUTPUT VOLTAGE (mV) S 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 30K 2 LOAD 50 40 30 -20. -10 O +10 +20 Pry (dBm) RETURN LOSS (dB) 100 Q LOAD 100 O LOAD FREQUENCY (GHz) OUTPUT VOLTAGE (mV) VIDEO RESISTANCE (ohms) -30 200 -10 FREQUENCY (GHz) INPUT POWER (dBm) +10 M/A-COM Ltd, Humphrys Road, Dunstable, Bedfordshire, LUS 4SX United Kingdom. Europe: (44) 1344 869595 2 North America: 800 366 2266 a Asia Pacific: (81) 3 3226 1671 387