Patent ID: 9608661
Date: 2017-03-28
CPC Classifications: H03F,H03M,H04B,H04L

Claim:
1. A transceiver front-end circuit for a cellular radio, said transceiver circuit comprising: an antenna structure operable to transmit signals and receive signals; a multiplexer coupled to the antenna structure and including a plurality of signal paths, each signal path including a bandpass filter that passes a different frequency band than the other bandpass filters and a circulator that provides signal isolation between the transmit signals and the receive signals; a receiver module including a separate signal channel for each of the signal paths in the multiplexer, each signal channel in the receiver module including a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal; and a transmitter module including a transmitter delta-sigma modulator for converting digital data bits to the transmit signals, said transmitter module including a tunable bandpass filter, a switch for directing the transmit signals to a particular signal path, and a power amplifier in each signal path for amplifying the transmit signal before transmitting.