In this paper, a wireless transceiver for digital data communications in the frequency of 1.8∼1.9GHz is designed and implemented. Direct up conversion transmitter and single down conversion receiver suitable for integration is used. This paper present design techniques for distortionless FM-PLL modulator and IF demodulator in the frequency of 110MHz. Modulator is made of PLL, Buffer and VCO, IF demodulator for GMSK signal which is implemented by LMX2411 use quadrature detection. FM-PLL modulator's characteristic is measured by using simple communication theory. Transceiver's performance using implemented modulator is tested by measuring transmission power spectral density and receiver sensitivity.
