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.

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

This paper presents design and development of an LNA based on balanced configuration for L-band radar application. Balanced configuration is the most suitable choice for concurrently meeting good matching, stability and linearity. Moreover, this configuration also offers inherent redundancy and added output power. In this scheme, the input and output couplers cancel out the reflections from the amplifiers and thus improve impedance matching. The bandwidth of balanced amplifier is dependent on both hybrid coupler and LNA's bandwidth. In this work, the targeted frequency band is from 1.0 to 2.0 GHz. The achieved gain is between 15 to 20 dB, noise figure is less than 2 dB and VSWR is less than 2.0 and output VSWR is less than 1.25. In the radar band i.e. 1.2 to 1.4 GHz, gain is 19 dB, noise figure is 1.1 dB and VSWR is less than 1.25.

A balanced LNA for L-band radar application

Low-Noise Amplifiers are key components in every communication receiving end. The LNAs primary purpose is to amplify the weak input signal, adding additional little noise. A SiGe Low-Noise amplifier at design frequency of 3.5GHz is presented. This paper includes the bias network design, Stability analysis, Matching Network Design and EM Co-simulation of the LNA. Gain of ≥15dB, Noise Figure of ≤1dB is achieved to make sure noise contribution of the amplifier is as low as possible. Keysight's Advance Design Software tool has been used for simulation. 

LNA Design for LEO Space S-Band Applications

Low-Noise Amplifiers are key components in every communication receiving end. The LNAs primary purpose is to amplify the weak input signal, adding additional little noise. A SiGe Low-Noise amplifier at design frequency of 3.5GHz is presented. This paper includes the bias network design, Stability analysis, Matching Network Design and EM Co-simulation of the LNA. Gain of ≥15dB, Noise Figure of ≤1dB is achieved to make sure noise contribution of the amplifier is as low as possible. Keysight's Advance Design Software tool has been used for simulation.

This paper describes the design and realization of a low noise amplifier (LNA) at 410MHz A balanced amplifier structure which consists of hybrid coupler and amplifier has been used to realize this LNA This approach gives the advantage of good voltage standing wave ratio, higher linearity and good stability Noise figure of 1dB with a flatness of 05 dB and input-output return losses better than-15dB have been achieved over 100MHz bandwidth The design is carried out with Advanced Design Systems software LNA has been realized on FR4 substrate, using SiGe HBT (BFY640) and chip type passive components

Balanced Amplifier Technique for LNA in UHF Band

The 4th order Crystal band pass filter has been designed and realized at a frequency of 71.61MHz with low insertion loss, high rejection at stop band and good input-output return loss. A coupled resonator ladder topology is used to realize the filter. AT-cut High Frequency Fundamental Mode (HFFM) crystal resonators are used. Four crystal resonators are used to meet the required specification. The HC-4S/U package of crystal resonators are used in this filter. Also design is realized with the help of computer aided software ADS.

Satish Nandanwar

Papers

Balanced Amplifier Technique for LNA in UHF Band

Design and realization of crystal band pass filter using discrete crystal resonators