A DIRECT CONVERSION RECEIVER EMPLOYING A FREQUENCY MULTIPLIED DIGITALPHASE-SHIFTING DEMODULATOR

Radio data receiver systems are being made smaller with lower power co nsumption and higher performance. Integrated circuits (IC) can be fitt ed into a direct conversion receiver, but this has not yet been found practical because it is difficult to ensure the performance. A novel a rchitecture is proposed for the wideband frequency shift-keying (FSK) quadrature demodulator, which is called the frequency multiplied digit al phase-shifting demodulator; and it has been used in a receiver. Thi s demodulator has been adopted as an IC for low bit rate FSK radio equ ipment such as paging receivers. It is confirmed that the direct conve rsion receiver has the required sensitivity, distortion, and power con sumption; and its usefulness is demonstrated.