A Highly Linear Wide-Band Tunable Lna for Military Radio Applications

Abstract

A wide-band tunable Low-Noise Amplifier (LNA) was designed to be used in military radios. The LNA works in the frequency range of 30–512 MHz where military walkie-talkies operate. To cover the wide range of operating frequencies, the output of amplifier is divided into four sub-bands with four separate external inductors and integrated capacitor arrays. The first part of the study analyzes the performance parameters such as the gain, tuning, matching, noise figure, and distortion. Layout of the design was completed, and post-layout simulations, including the layout parasitic effects, were run to quantify the performance. The LNA achieves a minimum of 12-dB gain across the entire operating frequency range. The minimum rejections achieved by the LNA at 10% and 20% offset from the center-tuned frequency were 7 dB and 13 dB, respectively. The LNA achieves a worst-case noise figure of 4.6 dB, and the impedance-match parameter (S11) is better than −20 dB under all the conditions. The worst cases P1dB (1-dB Compression Point) and IIP3 (3rd Order Input Intercept Point) were 9.1 dBm and 18 dBm, respectively, across frequency and process–voltage–temperature corners. The design dissipates 20 mA from a 3.3-V power supply and uses a 1.5-V power supply for capacitor array termination.