ABSTRACT
In the system of shortwave air communication, the radio frequency circuit carries on work under the high-frequency condition. So, need to utilize the circuit theory of the radio frequency to understand the operation principle of circuit of the radio frequency. The ordinary design circuit under the high-frequency condition , stray electric capacity and impact on circuit of the stray inductance are very great. So, I adopt the integrated circuit design method to avoid some shortcomings of some simulation circuit.
The radio frequency integrated circuit developed rapidly,in order to be engaged in the wireless digital audio frequency, the data transmission system of digital video , wireless remote control and telemetering measurement system, wireless data collecting system, wireless network and wireless safe precaution system,etc. are designed, solve the wireless calmness that uses and offer the greatest possibility.
Include in the radio frequency circuit of the wireless communication system of the whole shortwave, the transceiver, the band-pass filter of intermediate frequency, baseband demodulation wave filter, the amplitude limiting level of the data, gain and control automatically, basic oscillator, close the function, such devices as I/O interface circuit ,etc., in order to realize the output of the signal of shortwave wireless communication and do simple processing to the signal that is received mainly, it is equivalent to the front equipment of shortwave wireless communication.
Key words： Radio frequency circuit ，PCB Design，shortwave communications
