Radio receiver and frequency generator for use with digital signal

Abstract

The present invention relates to a radio receiver, particularly to a receiver for use in single-frequency applications, such as GPS, and to a frequency generator, which may be used in such a radio receiver, or elsewhere. The frequency generator comprises a tuned circuit connected between the emitter of the transistor and ground, such that a voltage signal at the basic frequency appears on the emitter terminal of the transistor. This arrangement has the advantage that the two frequencies appear on separate ports, and provides a radio receiver including radio receiver circuitry for connection to digital signal processing circuitry, reducing the complexity of the overall circuit. Additionally, there is a radio receiver wherein separate first and second local oscillator signals are generated from the terminal of s single transistor, avoiding the need for cascade multiplication stages, again reducing the size and complexity of the overall circuit. Further, circuitry is included generating an oscillator signal whereby the signal processing means tolerates the resulting frequency errors, and a single frequency direct downconversion receiver, comprising means for sub-sampling and one-bit coding the demodulated signal, and a transistor capable of decoding a microwave local oscillator signal and a digital signal processor with a clock signal for tolerating frequency errors.