UHF Power Amplifier for Professional Mobile Radio
Created: Apr 16, 2015
No description available.
Professional Mobile Radio, commonly known as Private Mobile Radio (PMR), is a portable, mobile base station, which provides two-way mobile radio communications. These systems were only able to communicate over relatively short distances. They used a single central base station to communicate with all the mobile stations. This considerably reduced their coverage area. To overcome this a system, known as trunking, was devised whereby several transmitters could be used and the signal was trunked to the correct station.
This reference design is designed to demonstrate the RF performance characteristics of the AFT09MS007N RF transistor when applied to the 350–470 MHz professional mobile radio band. This 350–470 MHz Professional Mobile Radio amplifier reference design is designed to utilize the standard 7.5 V power supply commonly used in vehicle mount applications. With no RF drive to the input, the supply voltage VDD is increased to 7.5 Vdc, and then VGS is increased to achieve desired IDQ. The RF input drive is then slowly increased until the required power level is measured at the RF output. Measurements are taken with output power set to 7 W at 350 MHz and 470 MHz. The fixture is tuned until the gain drop between the two different power levels is less than 1 dB at both frequencies. Once tuned, CW measurements with the output power set to 7 W are performed at 350 MHz, 410 MHz and 470 MHz.
Private Mobile Radio is a convenient way of communication especially in rural areas since it does not require network coverage. It is widely used by many taxis and courier firms, security guards and utility companies. The AFT09MS007N RF transistor is designed for mobile two-way radio applications with frequencies from 136 to 941 MHz. The high gain, extreme ruggedness and broadband performance of this device make it ideal for large signal, common-source amplifier applications in mobile radio equipment.