A Wideband Functionality-Reconfigurable RF Building-Block With Four Operating Modes

In this brief, a wideband functionality-reconfigurable RF building-block with in-phase/out-of-phase powering dividing (PD) and single-/dual-band Single-Pole-Double-Throw (SPDT) filtering switching modes is proposed utilizing a novel Switched Central-Loaded Parallel Coupled-Line (SCLPCL) structure. By independently forward- or reverse-biasing the four PIN diodes in the SCLPCL structure, three reconfigurable sub-block statuses (Status I, II and III) can be obtained, which further leads to four operating modes of the whole building block. With the aid of the stepped-impedance compensation network and the Central Loaded Short-Circuited Stubs (CLSCS), the 180 degrees phase-shift difference at two achieved pass-through statuses (Status I and II) can be balanced, together with an enhanced out-of-phase bandwidth. In addition, the compensation network can also be used to ease the trade-off between wide out-of-phase bandwidth at the pass-through statuses and high isolation at the isolated circuit status (Status III). The SCLPCL is further modified and optimized to achieve the three-port functionality-reconfigurable RF building-block. The implemented prototype demonstrates a wide bandwidth in all modes. Moreover, less PIN diodes are applied to obtain more operating modes, verifying the simplicity of the proposed method to design functionality-reconfigurable RF circuits.