Design High Gain PHEMT LNA for Wireless Application at 5.8 GHz Pongot K, Othman A.R, Zakaria Z , Suaidi M.K, Hamidon A.H, Hamidon J.S, Ahmad A Abstract— This research present a design of a higher gain (68.94dB) for PHEMT LNA using an inductive drain feedback technique for wireless application at 5.8GHz. The amplifier it is implemented using PHEMT FHX76LP transistor devices. The designed circuit is simulated with Ansoft Designer SV. The LNA was designed using inductive drain feedback, inductive generation to the source, and the T-network as a matching technique was used at the input and output terminal. The low noise amplifier (LNA) provides a noise figure 0.64 dB and gain (S 21 ) of 68.94 dB. The output reflection (S 22 ), input reflection (s 11 ) and return loss (s 12 ) are -17.37 dB, -15.77 dB and -88.39 dB respectively. The measurement shows the stability were at 4.54 and 3-dB bandwidth of 1.72 GHz. The input sensitivity is -92 dBm exceeded the standards required by IEEE 802.16. Keywords- IEEE 802.16; Cascaded and Cascoded LNA; Inductive drain feedback, PHEMT LNA 1. INTRODUCTION At this point, most of the developing and advanced country used 3G technologies due to the speedy delivery of information to users at a higher bit rate. However, the bit rate of 3G technology reserve at this point is still not enough due to the high demand from consumers, especially in wireless broadband. To overcome this problem, the use of WiMAX technology was introduced to consumers to enable effective connectivity at high bit rate to a new generation of consumer devices for adaptation latest applications that are available in the market (Lowe, 2007). Pongot K., Ahmad A Bahagian Sumber Manusia, Majlis Amanah Rakyat (MARA) Malaysia kamilpongot@yahoo.com.sg, azmanahmad888@gmail.com Othman A.R, Zakaria Z, Suaidi M.K, Hamidon A.H, Hamidon J.S Universiti Teknikal Malaysia Melaka line 1 College / University Name Malaysia rani@utem.edu.my,zahriladha@utem.edu.my,kadim@utem.edu.my, hamid@utem.edu.my, jsamhamidon@yahoo.com. Groups of telecommunication protocol using WiMAX technology as a new trademark and standards in the provision of mobile and fixed internet access. Residential construction and opening of a planned township enterprises in free zones require high data transfer rate (70 Mbps) and reach (50 km) to meet the needs of high bandwidth voice and data to support the growth of the industry (Othman et al., 2012). WiMAX is a replacement technologies for cellular phone technologies such as UMTS and GSM and can be used to increase capacity of the customer (AbdulRahman, 2008). Therefore, the RF front- end receiver should be design according to the latest specifications to support new trademark as set by the telecommunications protocols and allows it to operate in a multiple of applications on a single device. Design of LNA amplifiers for RF receiver front-end to obey and comply with the new standards IEEE 802.16 to ensure that the received signal can be processed to obtain information that is transmitted without interference noise. This can only be done when the designers are able to design RF front-end receiver with the best characteristic in the entire system such as the higher gain, low noise figure and sufficient bandwidth to accommodate the needs of the latest applications available in the market for users using WiMAX technology. To ensure high performance signal reception to meet the standards set by IEEE 802.16, a new design in architecture receiver RF front-end should be introduced to improve the performance of existing systems. Previous researcher reported covering the extension of communication distance for the system up to 50km requires overall gain from the range up to 50 dB (Othman et al., 2010), but to get a better performance for RF front-end receiver, we proposed for overall gain that introduce enhanced up to 65 dB. For WiMAX standard, the system is designed to accommodate up to 200 channel subscribers while the bandwidth of the system designed is between 1600 to 1700 MHz, which is triple than the standard 20 MHz for 200 sub-carriers. In addition, the noise figure proposed by the IEEE 802.16 (WiMAX) for the RF receiver front-end architecture must be less than 3 dB. The input sensitivity of the system should cover the minimum sensitivity of -80 dBm (Othman et al., 2010). Proceeding of International Conference on Electrical Engineering, Computer Science and Informatics (EECSI 2014), Yogyakarta, Indonesia, 20-21 August 2014 456