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The authors describe a signal-chip radio receiver for VHF and UHF digital wide-area paging transmissions up to 500 MHz with frequency-shift-keying (FSK) data rates up to 1200 Bd. All channel filtering is on-chip and the IC requires only 28 surface mounted external components and a quartz crystal to make a complete receiver. With -126-dBm sensitivity, 70-dB adjacent channel rejection, and 60-dB intermodulation immunity, it satisfies all known pager specifications, worldwide, using the POCSAG paging code. High-dynamic-range mixers, integrated gyrator filters, small-area high-pass filters, and an efficient FSK demodulator combine to give good performance with a current consumption of only 2.7 mA from a 2-V supply. High-density on-chip capacitors in a bipolar process designed for analog RF applications give a chip size of only 4.6*3.8 mm. > |
