Conventional application areas Shortwave radio refers to radio communication equipment with a working wavelength of 100 to 10 meters (frequency of 3 to 30 MHz). It is mainly used to transmit voice, constant amplitude and frequency shift messages. When transmitting telephone signals, amplitude modulation and single sideband modulation are used. It consists of a transmitter, a receiver, an antenna, a power supply and terminal equipment. It is generally divided into portable, vehicle-mounted and fixed radios. It has the characteristics of small size and light weight. It usually uses a whip antenna and uses ground waves for short-range communication. The power is usually several watts to tens of watts. Military shortwave radios are divided into portable, vehicle-mounted (or ship-mounted, airborne) and fixed radios according to their purpose and conditions of use. Portable radios are mainly used to ensure the communication of tactical units. They have the characteristics of small size and light weight. They usually use whip antennas and use ground waves for short-range communication. The power is usually several watts to tens of watts. Vehicle-mounted radios are used to form command post communication hubs or for mobile communications. Their power is tens of watts to several kilowatts. Generally, whip antennas and dipole antennas are used. Fixed radio stations are mainly used for strategic communications, usually consisting of a concentrated sending station and a concentrated receiving station. Their power ranges from hundreds of watts to thousands of watts, or even tens of kilowatts. They generally use large antennas with good performance. In order to use ground wave communications, the frequency range of portable and vehicle-mounted radio stations has been expanded to the medium wave band, usually 1.6 to 30 MHz. Self-developed, real picture
Test data of several power amplifiers + filters
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