Frequency-tunable feedforward amplifier for PCS applications

A novel linear feedforward amplifier with channel tunability was developed for multicarrier wireless communications applications. This amplifier is de signed to operate in the personal communication services (PCS) frequency ra nge with a maximum output power of 27 dBm, and offers frequency selectivity by using variable attenuators and variable phase shifters in both the sign al and error cancellation loops. The circuit is capable of achieving a vari able tuning range of 195 MHz with an intermodulation cancellation of over 6 0 dBc, and a third-point intercept point improvement of more than 15 dB. (C ) 1999 John Wiley & Sons, Inc.