Power divider with wideband harmonic suppression for center-fed antenna arrays

In this paper, a center-fed four-way power divider with wideband harmonic suppression is proposed. A distinguishing feature is the use of sectorially modified Gielis curves (SMGCs) for open stubs, shorted stubs, and stub-loaded coupled-line structures, providing more degrees of freedom in the designs to suppress the wideband harmonics. The expressions for the SMGCs, along with the ABCD matrix elements of the stub-loaded coupled-line structure having different even and odd mode electrical lengths (theta(ec) not equal theta(oc)) are another distinguishing features presented in this work. The novelty is to use two stages (first and second) with a combination of open, shorted, coupled-line stubs and tapered transmission lines to achieve good impedance matching and wideband harmonic suppression for center-fed antenna arrays. The proposed center-fed four-way power divider achieves a wideband harmonic suppression of up to 4f(o) and a relatively wide -10 dB impedance bandwidth of 52%. The proposed power divider is used in a horizontally-polarized antenna array for wireless L-band applications.