subject: Digital Tv Transmitter Power Amplifier Design (with Photos) [print this page] LDMOS process technology combines the BPT and GaAs process. And standard MOS technology is different in the device package on, LDMOS not used beryllium oxide BeO insulating layer, but directly Yingjie in the substrate, thermal conductivity, improved heat resistance of the device, greatly extend the life of the device . Since the negative temperature effect LDMOS tube, its leakage current in the heat automatically when both flow and does not like being bipolar tube temperature effect on the formation of the collector current local hot spots, so easy to damage the pipe. So LDMOS tube greatly enhance the load mismatch and over-stimulate the appetite. Also thanks to the automatic current sharing control LDMOS role of the input - output characteristic curve in 1dB compression point (the use of large-signal saturation section), the more moderate bent, so the dynamic range was increased, benefit analog and digital TV RF signal amplification. LDMOS small signal amplification in approximately linear time, little or no distortion, very much simplifies the circuit. DC gate current of MOS devices is almost zero, the bias circuit is simple, without complex temperature compensation is active with low-impedance bias circuit.
Digital Tv Transmitter Power Amplifier Design (with Photos)
