Fsk modulation signal receiver with high sensitivity in low rate mode

Abstract

The receiver () for FSK modulation signals includes an antenna () for receiving modulated data or control signals, a low noise amplifier () for amplifying and filtering the signals picked up by the antenna, a local oscillator () with a quartz resonator () for supplying high frequency, in-phase signals (S), and high frequency, in-quadrature signals (S), first and second mixers () for mixing the high frequency, in-phase and in-quadrature signals with the filtered and amplified incoming signals, in order to generate intermediate signals (I, Q), and a filtering unit () for filtering the intermediate signals. The receiver can be configured to receive modulated data or control signals at low rate. The filtering unit supplies intermediate signals (I, Q) filtered in a polyphase filter () to a first demodulation stage in medium or high rate mode, or intermediate, baseband signals filtered in the polyphase filter, which is converted into two low-pass filters (), to a second demodulation stage in low rate mode.