Patent ID: 8411799
Filing Date: 2013-04-02
Classification: H03D

Abstract:
1. A receiver having an intermediate frequency error correction circuit comprising: a mixer having a source input, a local oscillator input, and an IF output, an adjustable frequency local oscillator having an output coupled to the local oscillator input of the mixer; an IF filter having an input coupled to the IF output of the mixer and an IF filtered output, where the IF filter has an IF filter frequency response; control circuitry coupled to the local oscillator such that the frequency of the local oscillator can be varied to at least partially correct an IF frequency error, said control circuitry including a demodulator coupled to the output of the IF filter, an averaging circuit coupled to an output of the demodulator, an ADC coupled to an output of the averaging circuit, and a digital controller coupled to an output of the ADC; and a limiting amplifier coupled between the IF filter and the demodulator.