Vhf, Uhf Radio Transmitter System Key Technology Research

Since the short wave is discovered that can be used in communications,short wave communication is expanding leaps and bounds.It is widely used in the fields of wireless communication and military communication.lt plays an important role in the department of government,military,diplomacy and meteorology. So improving the quality of short wave communication is becoming the most pressing demand of the day. However, scientists in many countries are working hard to remove the interference of harmonic and noise, and trying to increase the transmission power of short wave radio station.This paper is based on a short wave radio station subject. Firstly, it will describe the characteristics and the realizing meaning of the modern short wave communication. Secondly, this paper will give the theory introduction of the parts which belong to the transmitter system of the short wave radio station. Also, it will give the gain simulation of the transmitter system and the simulation of local frequency, the description of the linearization technology of the wide-band amplifier which is called the hard-core of the transmitter system will be given,too. Thirdly, it will give an improvement plan that adds a filter group into the system to restrain the second harmonic. And then it will give the software design and simulation of the filter group, after that, the performance of the filter group will be tested. Fourthly, based on the amplifier that has been manufactured, a 4-way symmetric lumped element Wilkinson power combiner will be designed in order to realize the high power output. On the last chapter, it will give the theory design process of the power combiner, the circuit and the software simulation results will be given also.