S. S. Gore et al. Int. Journal of Engineering Research and Application www.ijera.com Vol. 3, Issue 5, Sep-Oct 2013, pp.552-557 www.ijera.com 552 | Page Parametric Performance Analysis of 2-GHz Low Noise Amplifier S. S. Gore 1 , G. M. Phade 2 1 (Department of Electronics & Tele-communication, PUNE University, India) 2 (Department of Electronics & Tele-communication, PUNE University, India) ABSTRACT In this paper designed, implemented and simulated LNA is divided into two parts. In the first part, LNA is based on lumped elements and in second part LNA is based on distributed elements. Two designed methods have been compared and best performance is obtained with lumped elements. The designed amplifier provides a noise figure of 0.358 dB , gain of 16.778 dB, input return loss is -4.917dB and output return loss is -10.045 dB. LNA is simulated at 2 GHz by employing active device like MESFET sp_hp_ATF34143_4_19990129. Parametric performance analysis is carried out using Advanced Design Simulation (ADS) tool of Agilent Technologies. This paper highlights or shows the all necessary steps or different performance parameters for LNA design. Keywords – ADS (Advanced Design System), LNA(Low Noise Amplifier), Smith Chart, S-parameters I. INTRODUCTION The amplifier is probably the most fruitful of all electronic circuit building blocks in a microwave/radio-frequency (RF) system. For amplification of microwave signals both vacuum tubes and solid state devices (Transistors) are used. Tubes such as klystron and Travelling wave tube (TWT) amplifiers are exclusively used for high-power applications, whereas solid state amplifiers are very suitable for low-noise and medium power levels. Solid state devices generally require low voltage for operation and they are very compact and light weight. These characteristics are particularly useful for space and military applications where weight and size can impose severe limitations on the choice of components and systems [5]. While microwave tube amplifiers are still sometimes required for very high power and/or very high frequency applications, continuing improvement in the performance of microwave transistors is gradually reducing the need for microwave tubes. BJT is used up to certain frequency due to their structure and manufacturing process but FET can be used for higher frequencies. several GHz [3]. Also FET consumes or dissipates less power and requires less area rather than BJT also having better noise immunity than BJT’s [8]. There are several kinds of FETs distinguished by the type of gate isolation shown in table 1.1. Table 1.1 Types of EFTs Device Gate Isolation MOSFET Oxide (SiO2) JFET P/n-Junction MESFET Schottky barrier diode When you applied high frequency to MESFET, offers better simulation results also second order effects are less as compared to JFET [9]. The Metal- Semiconductor-Field-Effect-Transistor (MESFET) consists of a conducting channel positioned between a source and drain contact region .The carrier flow from source to drain is controlled by a Schottky metal gate. The control of the channel is obtained by varying the depletion layer width underneath the metal contact which modulates the thickness of the conducting channel and thereby the current between source and drain. The key advantage of the MESFET is the higher mobility of the carriers in the channel as compared to the MOSFET. Fabrication process of MESFET and JFET is also easy or simple than MOSFET. Hence MESFET sp_hp_ATF-34143_4_19990129 is used in this project to implement and simulate the LNA. Lumped elements (Inductor and Capacitors) and Microstrip, which containing distributed elements (MLIN-Microstrip line and MLOC- Microstrip Open- Circuited Stub) are used to overcome the drawbacks of other methods [4]. II. CIRCUIT DESIGN In this paper or project circuits is designed and implemented using lumped element and distributed element. 2.1 Lumped elements Meaning of lumped element is, discrete object that can exchange energy with other , An object whose internal physics can be combined into terminal relations, Whose size is smaller than wavelength of the appropriate and signals do not take time to propagate [15-19]. Fig.1 Lumped model [7] RESEARCH ARTICLE OPEN ACCESS