BJT Feedback LNA with Input Port Simultaneously Signal and Noise Matched

This paper presents the first implementation of a novel technique for designing feedback low noise amplifirs (LNA) with Simultaneous Signal and Noise Matching (SSNM) at the input port. The design procedure relies on a new and original analytical approach that determines the exact value of the feedback element(s) in order to design either the complex value of the optimum noise source reflection coefficient ¿Sopt or its magnitude. The goal is to overcome the problem with a microwave amplifier that the maximum signal power transfer from the source to the active device cannot be achieved simultaneously with its minimum noise figure. The theoretical approach does not depend on a particular device, nor is it restricted to a given frequency. The LNA makes use of a BJT and commercially available surface mounted components. The good agreement between experimental and simulated results confirms that this new design technique can be applied successfully.