System for short-range transmission of signals over the air using a high frequency carrier

摘要

A system is provided which transmits either analog or digital data signals over the air. The system includes including a transmitter and a receiver. The transmitter and receiver are arranged to transmit signals using a carrier signal having a high frequency such as in the range of 902-928 MHz. The transmitter and receiver are configured to provide for the transmission of two channels of stereophonic signals while maintaining high signal-to-noise ratios, good frequency response, and low distortion. To provide for the proper transmission of signals between transmitter 10 and receiver 12, these devices include oscillating circuits having ceramic resonators which provide a base frequency which is readily modulated to facilitate proper transmission of either analog or digital signals between the transmitter and receiver. To further improve the transmission capability between the transmitter and receiver, the transmitter and receiver both include substantial buffering, isolation and shielding between selected circuit components to prevent unwanted areas of frequency modulation within the transmitter and receiver.