Reconfigurable Circuits for Multi-band Application Based on Different Two-port Impedance Matching Networks

Several new kinds of reconfigurable circuits will be presented in this talk, including impedance matching networks, power dividers and couplers with wide tunable ranges or multi functions. Firstly, several two-port impedance matching networks based on tunable capacitors and switches are proposed and analyzed. Analytical equations for matching different loads at different operating frequencies are derived for the impedance matching networks. Furthermore, to extend the function of the impedance matching networks, the design methods for wide-band operation and controlling phase shift are proposed and experimentally verified, respectively. Based on the proposed two-port impedance matching networks with tunable capacitors, two-way equal and unequal power dividers with tunable frequencies are proposed, which can achieve tunable frequency range of nearly 100%. In addition, a compact coupler with tunable frequencies and coupling coefficients simultaneously is proposed, while a 90° phase difference between the two output ports can be realized during tunable process. Based on the proposed two-port impedance matching networks with switches, a power divider with reconfigurable power dividing ratios is proposed. The reconfigurable power divider can switch between a large power ratio and a small power ratio, while the return loss and isolation keep good performance. Furthermore, to verify the practicability of the proposed circuits for reconfigurable systems, an antenna array with tunable operating frequencies is designed and measured, which can achieve tunable frequency range of 70%. In addition, an amplifier with wide reconfigurable bands is designed and fabricated, which can switch between different bands and achieve nearly 20% operating bandwidth in each band.The above work takes the features of wide reconfigurable range, simple structure and multi functions. With these features, the proposed circuits are particularly suitable for reconfigurable systems in wireless communication.