SDUS front-end for the Meteosat Satellite System Technical specications - Version 0.2 March 15, 2002 Contents 1 Antenna System 2 2 Low-noise Amplier (LNA) 2 2.1 General Specications............................. 2 2.2 First stage.................................... 2 2.3 Second stage................................... 3 2.4 PCB microwave laminates........................... 3 3 Local Oscillator Synthesizer 4 3.1 General Specications............................. 4 3.2 PLL integrated circuits............................. 4 3.3 Voltage controlled oscillators (VCOs)..................... 4 3.4 PCB microwave laminates........................... 4 4 Downconverter 5 4.1 General specications.............................. 5 4.2 MMIC ampliers................................ 5 4.3 PCB microwave laminates........................... 5 5 Microstrip Filters 6 5.1 Low-pass lter.................................. 6 5.2 Band-pass lter................................. 6 5.3 PCB microwave laminates........................... 6 1
1 Antenna System The receiving antenna is based on a primary focous parabolic mesh dish reector and a circular horn feed with a monopole probe. Parameter Value Units Dish Diameter 3.1 m Reector material Al Eciency 55 % f/d ratio? Theoretical Gain at 1.7 GHz (πd/λ) 2 35 db 2 Low-noise Amplier (LNA) The LNA is a two-stage amplier and will be mounted directly on the antenna horn feed to minimize noise gure. Power to the LNA should be supplied via the output RF port but provision of separate power supply terminals should be accounted for. 2.1 General Specications Parameter Symbol Value Units min. typ. max. Frequency range [f L f U ] 1690 1696 MHz Gain G 27 30 db Gain atness G ±0.5 db Output 1dB compression P 1dB 0 dbm Input impedance Z in 50 Ω Output impedance Z out 50 Ω Input VSWR VSWR(in) 1.2:1 Output VSWR VSWR(out) 1.2:1 Noise gure F 0.7 1.0 db RF Connectors SMA or N (female) Supply voltage V DC 6 14 V Supply current I DC 100 ma Estimated cost 50 Euro 2.2 First stage Based on a very low-noise GaAs FET transistor in a common source conguration. The source transistor leads should be directly tied to the ground plane using via through holes as close as possible. 2
A variable negative gate bias supply should be provided. This stage should have no less than 10 db of gain. Available GaAs FET transistors Manufacturer Model Type Cost factor Agilent ATF-21186 General Purpose GaAs 1.0 Agilent ATF-10136 High performance GaAs 2.0 Agilent ATF-36077 GaAs Pseudomorphic HEMT 2.0 Agilent ATF-34143 GaAs Pseudomorphic HEMT 1.8 NEC NE32984D GaAs Pseudomorphic HEMT 2.0 NEC NE32584 Pseudomorphic HJ GaAs FET 2.0 NEC NE3210S01 HJ GaAs FET 1.0 2.3 Second stage Based on a monolithic amplier integrated circuit (MMIC) The same care should be taken regarding the ground connection of the MMIC ground leads (via holes as close as possible) Available MMIC ampliers Manufacturer Model Process Cost Factor Sirenza Microdevices SGA-4586 SiGe 2.7 Sirenza Microdevices SGA-6586 SiGe 2.7 Mini-circuits ERA-3 GaAs HJ Bipolar 1.3 Mini-circuits Gali-55 InGap HBT 1.0 Agilent INA-02186 Si 2.4 2.4 PCB microwave laminates Specications of the PCB laminate should be carefully chosen towards low dissipation factors substrates and low dielectric thicknesses (to minimize ground inductances). Rogers Corp. RT/Duroid 5870 2.33 0.031 0.0012 1.0 Rogers Corp. RT/Duroid 5880 2.20 0.031 0.0009 4.0 Rogers Corp. RT/Duroid 5880 2.20 0.015 0.0009 2.7 GIL Technologies GML 1000 3.20 0.030 0.003 1.0 GIL Technologies GML 1000 3.05 0.020 0.003 1.0 3
3 Local Oscillator Synthesizer The receiver local oscillator is based on a microprocessor controlled PLL synthesizer. The output frequency should be stored on a non-volatile memory (EEPROM) and programmed via a serial interface (EIA-232). 3.1 General Specications Parameter Symbol Value Units min. typ. max. Frequency range [f L f U ] 1500 1900 MHz Frequency step f step 100 khz Output power P out 6 8 dbm SSB phase noise (@100 khz oset) P N -120 dbc/hz Output impedance Z out 50 Ω Output VSWR VSWR(out) 1.8:1 RF Connector SMA (female) Supply voltage V DC 24 V Supply current I DC 120 ma Estimated cost 70 Euro 3.2 PLL integrated circuits Manufacturer Model Type Freq. range (GHz) Cost factor National Semiconductors LMX-2326 Integer N 0.1 2.8 1.0 National Semiconductors LMX-2353 Fractional N 0.5 2.5 1.0 Analog Devices ADF-4112 Integer N 0.2 3.0 1.8 3.3 Voltage controlled oscillators (VCOs) Manufacturer Model Freq. range (MHz) Output Power Cost factor Mini-circuits POS-2000A 1370 2000 +12 dbm 1.0 Mini-circuits ROS-1900V 1450 1900 +8 dbm 1.2 3.4 PCB microwave laminates Rogers Corp. RT/Duroid 5870 2.33 0.031 0.0012 2.0 GIL Technologies GML 1000 3.20 0.030 0.003 2.0 FR-4 or G-10 4.8 0.062 0.003 1.0 4
4 Downconverter The downconverter is based on a double-balanced mixer, the ADE-20 from Mini-circuits, inserted between two MMIC ampliers, providing adequate signal level to demodulator receiver. 4.1 General specications Parameter Symbol Value Units min. typ. max. Frequency range (RF port) [f RFL f RFU ] 1500 2000 MHz Frequency range (IF port) [f IFL f IFU ] DC 300 MHz Conversion gain Gc 30 db LO level P LO 7 dbm I/O impedance Z out 50 Ω Input / Output VSWR VSWR 1.8:1 RF Connectors SMA (female) Supply voltage V DC 6 14 V Supply current I DC 100 ma Estimated cost 50 Euro 4.2 MMIC ampliers Manufacturer Model Process Cost Factor Sirenza Microdevices SGA-4586 SiGe 2.7 Sirenza Microdevices SGA-6586 SiGe 2.7 Mini-circuits ERA-3 GaAs HJ Bipolar 1.3 Mini-circuits Gali-55 InGap HBT 1.0 Agilent INA-02186 Si 2.4 4.3 PCB microwave laminates Rogers Corp. RT/Duroid 5870 2.33 0.031 0.0012 1.0 Rogers Corp. RT/Duroid 5880 2.20 0.031 0.0009 4.0 GIL Technologies GML 1000 3.20 0.030 0.003 1.0 GIL Technologies GML 1000 3.05 0.020 0.003 1.0 5
5 Microstrip Filters There are two types of microstrip lters to be designed: a low-pass and a band-pass response type lters. 5.1 Low-pass lter... 5.2 Band-pass lter... 5.3 PCB microwave laminates Specications of the PCB laminate should be carefully chosen towards low dissipation factor substrates. Very low strip widths should be avoided as the PCB fabrication process does not ensures tight tolerances. Rogers Corp. RT/Duroid 5870 2.33 0.031 0.0012 1.0 Rogers Corp. RT/Duroid 5880 2.20 0.031 0.0009 4.0 Rogers Corp. RT/Duroid 5880 2.20 0.015 0.0009 2.7 GIL Technologies GML 1000 3.20 0.030 0.003 1.0 GIL Technologies GML 1000 3.05 0.020 0.003 1.0 6