Non-Reflective Broadband Microwave Gain Equalizer for EW Applications

This paper presents design and development of a nonreflective broadband microwave gain equalizer with positive linear gain slope profile and operating over 1-18 GHz frequency range. This equalizer is well matched at all frequencies and it need not be used in conjunction with external attenuator or isolators. It is used for compensating the frequency dependent gain variations of wideband EW subsystems / systems. A design methodology is proposed for broadband linear gain slope equalizer. It is simulated in microstrip line technology for the gain slope of 0.7dB/GHz, linearity of ±1.3 dB and VSWR of 2:1 over 1-18 GHz frequency range. Equalizer circuit is realized on a 10 mil thick RT 5880 laminate. Measured results of the developed equalizer show that input/output VSWR is better than 2.08:1 and linearity in gain slope is ±1.3 dB over 85% of desired frequency band. Measured results show a good agreement with simulated results.