A UHF Broadband Low-Noise Amplifier for Active Digital TV Antenna

A broadband low-noise amplifier has been developed for an active digital TV antenna to operate in the frequency range of 470 - 800 MHz in the UHF band. The amplifier employs a SiGe:C Heterojunction Bipolar Transistor (HBT) and uses shunt negative feedback to achieve relatively flat gain and low return loss over a broad bandwidth. The amplifier prototype is fabricated on the 0.4-mm FR4 substrate. The measured results show that the gain of about 24 dB, the input return loss of better than 11 dB, and the noise figure of less than 1.4 dB are achieved throughout the desired frequency band.