Design Of Ultra High Power Ultra Low Noise RF Transceiver Module In 2.4G WLAN

With the rapid development of mobile Internet applications, Wireless Local Area Networks (WLAN) become a new generation of high-speed wireless access networks. Wi-Fi is an important form of wireless access technology, which can realize high speed local area connection. With expanding application field of Wi-Fi, requirements on transceiver system become more strict. When wireless signal transfer at 2.4GHz or 5GHz, the short wavelength cause large loss of power and short reach. The higher working frequency, signal in the propagation loss is bigger, which hinder the further development of Wi-Fi remote applications.This paper presents a 2.4GHz WLAN high-power RF transceiver module, a transmission path using two power amplifier. The first stage use a high-gain and high-linearity amplifier as the drive class, both to ensure the subsequent stage high power amplifier input requirements, but also to the output of the first stage has good linearity, providing a guarantee to the linearity transmit channels. The output stage uses high-power LDMOS power amplifier with higher output power,which can effectively solve the problem of limited signal transmission. Receiving channel uses two levels of ultra-low-noise LNA to improve the gain of the receiving channel, it has lower noise and higher receiver sensitivity. The transceiver module, using the TDD mode, use different time slots are turned receiving path, effectively reducing the interference transceiver path. After the completion of each module circuit design, whole signal source circuit schematic use AWR Microwave Office simulation software simulation, and produced according to the RF signal source overall PCB board laminated distribution, line width design, placement and routing rules hardware circuit.test results show that the module receiving path has gain of 30dB, noise figure less than 2.5dB, transmit path maximum transmission power of 44.8dBm (30W), linear output power up to 37dBm (5W), and gain flatness of less than 1dB. Entering 802.11g 54 Mbps OFDM modulation signal corresponding to the measured EVM is-32.2dB, equivalent to a percentage of 2.5%, in line with the design requirements.This high power RF transceiver module can be used for wireless access point, as well as application of wireless bridge and base station construction. The simple module network, wide area covered, to extend the application range of the wireless access point and wireless local area network has important significance. This module makes the bigger coverage of base station, not only reduces the communication cost, also can improve the communication quality.