Saw-less, LNA-less low noise receiver

摘要

A low noise receiver includes a downconverter configured to receive a radio frequency (RF) signal, the downconverter comprising a switching architecture configured to generate a plurality of output phases based on a respective plurality of local oscillator (LO) signals, a differencing circuit configured to combine the plurality of output phases such that an nth output phase is differenced with an (n+K)th output phase, resulting in gain-added output phases, and a summation filter configured to receive the gain-added output phases and configured to combine the gain-added output phases such that a response of the receiver effectively reduces odd harmonics of the RF signal.

主权项

1. A low noise receiver, comprising:
a passive low pass filter configured to filter a radio frequency (RF) signal directly from a switch module and to provide a voltage gain to the RF signal, the passive low pass filter including an impedance matching circuit and further configured to reduce a level of an interfering signal occurring at a frequency that is a seventh harmonic of the frequency of the RF signal; a downconverter coupled to the passive low pass filter and configured to receive the filtered RF signal, the downconverter including a switching architecture configured to generate a plurality of output phases based on a respective plurality of local oscillator (LO) signals, each of the plurality of output phases corresponding to a different phase within an LO period, the plurality of output phases being organized into at least K groups, K being an integer greater than one, each nth group of the K groups including an nth output phase of the plurality of output phases and an (n+K)th output phase of the plurality of output phases; a differencing stage configured to combine the plurality of output phases such that the nth output phase of each respective group of the K groups is differenced with the (n+K)th output phase of the respective group, resulting in gain-added output phases; and a summation filter configured to receive the gain-added output phases and configured to combine the gain-added output phases such that a response of the receiver effectively reduces odd harmonics of the RF signal including the third and fifth harmonics of the RF signal.