Design And Implementation Of0.9/2.14GHz Dual-Band Power Amplifier

Power amplifier (PA) is one of the important parts in RF front-end of transmitter for wireless communication systems. Its performance influences the quality of communication severely, and the power dissipation in PA plays a key role in determining the whole cost of system. With the rapid development of wireless communications, many traditional single band communication systems are changing into multi-band ones. Nowadays,3G, LTE, WLAN and some other systems are all operating at multi-band. In order to meet the requirement of multi-band, transceivers of wireless communication systems must be able to work at more than one band. In this way, the communication equipments can be smaller, more flexible, and cheaper. As a consequence, design and implementation of dual-band PA is of great significance. Today, people are paying more and more attention on the realization of dual-band PA.This paper is for the design and implementation of a0.9/2.14GHz dual-band PA. As dual-band PA has the same basic theory with traditional single-band PA, the basic theory of PA as well as the dual-band PA is involved in this paper. Then, the dual-band matching networks, dual-band bias circuits and dual-band DC-Blocks are designed, respectively. To design a whole dual-band PA, ADS is used for simulation. And at last, a fabricated dual-band PA is realized.The achievement in this paper is reflected by the following aspects:(1) A novel dual-band matching network is proposed, which contains a Pi-structure. The circuit has a short length and is able to match frequency-dependent complex loads concurrently. Simulation and measurement show that the matching network is easy to be realized with microstrips and the matching bands are wide. In addition, the design does not require complex calculation.(2) Research on the shift of resonant frequency in capacity-based dual-band DC-block is done, and the corresponding revised method is given in this paper. The phenomenon that resonant frequencies shift when two capacities are soldered in parallel is pointed out in this paper and the reason is discussed based on the high-frequency characteristic of capacities. And these are proved to be right by measurement.(3) A0.9/2.14GHz dual-band PA is realized. The bandwidths at0.9GHz and2.14GHz are85MHz and100MHz, respectively. And the measured output power reaches10W at both0.9GHz and2.14GHz.The designed power amplifier has a novel structure and the measurement is very well. As a consequence, the methodology has good application value.