A Digitally Controllable Passive Variable Slope Gain Equalizer for Wideband Radio Frequency System-on-Chip Applications

Abstract

A wideband fully integrated digitally controlled high linearity RF gain slope equalizer is presented in this work. The gain slope equalizer is realized using a modified bridged T attenuation network. The bridged resistor in the network is digitally controlled using a combination of series resistors connected in parallel to NMOS switches to vary the attenuation level. A gain slope tuning range of 2.39 dB/GHz to 6 dB/GHz is achieved for a frequency band of 200 MHz to 1.85 GHz. The effectiveness of the proposed equalizer circuit is demonstrated by integration on an RF transceiver ASIC. The digital controllability makes the proposed circuit highly suitable for system-on-chip RFICs.