FA4489 precision supercomponents for critical applications FA4489 9 channel preselector ultra low intermodulation distortion 1 mhz - 1200 mhz features ? ultra low intermodulation distortion ? 9 channels ? low insertion loss over all bands ? low amplitude ripple ? sharp attenuation ? fast switching speed ? low switching transients ? small size and low weight ? full mil ? low cost description the comstron model FA4489 is a switchable filter mod- ule with the capability of selecting any one of nine chan- nels with a four ttl control signal. this device is used as the front-end preselector in a high dynamic range receiver. the filter module introduces very low inter- modulation distortion along with low insertion loss - a necessary requirement for excellent receiver perfor- mance. ultra low intermodulation distortion comstron has developed a proprietary switching matrix that spans 1 mhz to 1200 mhz (more than 3 decades wide) along with introducing low intermodulation dis- tortion and low signal loss. the pin diodes utilized in the sp9t switch are optimum for high- lifetime carrier, low junction capacitance and low series resistance and help produce second and third order output intercept points (ip 2 and ip 3 ) of 90 dbm and 45 dbm respectively.
FA4489 ip 2 test setup for channel 2 and 3 performance 90 dbm level adret model 7100a signal generator set for 25 mhz adret model 7100a signal generator set for 30 mhz bandpass filter 33.4 mhz 20 mhz 3 db pad 10 db pad 3 db pad 10 db pad 10 db pad bandpass filter 93.1 mhz 55.8 mhz comstron FA4489 preselector spectrum analyzer hp8568a res.bw=10hz video bw=3hz rf att=30db span=100hz mc-zsc-2-1 power splitter bandpass filter 33.4 mhz 20 mhz
FA4489 precision supercomponents for critical applications 9 channels with sharp attenuation each of the 9 channel filters is composed of 12 pole pseudo-elliptic function lumped component (lc) elements. these elements are optimized to provide the highest amount of attenuation for the given package size. the fil- ters provide a minimum of 60 db/octave and provide an ultimate attenuation of 50 db minimum to 5000 mhz. s p 9 t s p 9 t rf in rf out drivers decoder 4 line ttl control input channel 1 functional block diagram channel 2 channel 3 channel 4 channel 5 channel 6 channel 7 channel 8 channel 9
FA4489 precision supercomponents for critical applications 35 south service road plainview, ny 11803 tel: 516-694-6700 fax: 516-694-2562 outline drawing specifications characteristics typical limits insertion loss across all bands 2.0 db 3.0 db passbands band 1 1-20 mhz .8 db 1.0 db max band 2 20-34 mhz .8 db 1.0 db max 3/4 octave each .8 db 1.0 db max band 9 640-1280 mhz .8 db 1.0 db max stopband attenuation 60 db/octave 50 db/octave min ultimate attenuation to 5000 mhz 55 db 50 db min vswr ( 50 ohms ) in/out all bands 1.4:1 1.5:1 max output intercept points 2 nd order + 92 dbm +90 dbm min 3 rd order + 47 dbm +45 dbm min switching speed 6 m sec 10 m sec max dc power + 5 v 140 ma max - 15 v 100 ma max weight 14 ounces mechanical configuration edge connectors with gpo rf in/out c o m s t r o n
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