Small Wireless Transceiver Design

VHF/UHF wireless transceiver possesses extensive applications, being of great value in research and development.A direction of development is the miniaturization and low-power dissipation of communication terminal.A completed wireless transceiver system usually consists of LNA, PLL, mixer, AGC, modulation and demodulation, RF and IF filter etc. If designing the transceiver system with discrete elements, the circuit will be very complicated, and the size of PCB is usually too larger or high-power dissipation. With the development of RF integrated circuit technique, the integrity of VHF/UHF band RF IC is more larger. There are some new RF IC integrated with transceiver function. Application of large-scale integrated circuit can simplify system design and save cost, and achieve miniaturization and low-power dissipation.This paper introduces primarly the design methods of miniaturization transceiver system based on tansceiver IC TH7122.TH7122 has some good characteristic, such as small acreage, low-power dissipation and completed functions.The inside receiver is a single-frequency conversion superheterodyne receiver . In the part of transmitter, modulation and up-conversion are processed at the same time.The integrated PLL circuit produces local oscillation, it can be tuned in wide band area,from 27MHz to 930MHz with good universal property. FM and FSK modulation modes are employed to transmit the analog and digital signals. By this way, this thesis implemented the experimental system.In the thesis, firstly expounds the configuration of tranceiver, the modulation principle of FM/FSK, and introduces the principle of PLL frequency synthesizer. Then, the system scheme analysis, the design of hardware, and some questions need paying more attention in system design and debugging are discussed in detail. The ultimate testing results are represented at last.