A planar ultra wide band single layer microstrip BALUN operating from 200MHz to 10GHz

Abstract

In this paper a new single layer BALUN is presented that covers the frequency range of 200MHz to 10GHz. The structure is composed of a two stage Wilkinson power divider followed by a wideband current flipping structure. Full wave simulations as well as measurements show that an amplitude imbalance of below 0.2dB and a phase imbalance of less than 5 degrees is achieved by this BALUN from 1.5GHz to 10GHz. Maximum phase and amplitude imbalance are 12degrees and 2dB respectively. The structure is very low loss with maximum insertion loss of 2dB and is matched at all the three ports with the maximum reflection coefficients of less than -10 dB in most of the bandwidth. The coupling between the two equally powered output ports is less than -10dB and the total length of the structure including the transitions to the connectors is 6.5cm.

Wideband Broadside-Coupled Line Baluns Enabled by Multimaterial Additive Manufacturing

“…Multilayer printed circuit board (PCB), low-temperature co-fired ceramics (LTCC), monolithic integrated circuits (MMICs), and CMOS, are among the most common integration technologies for the realization of compact planar baluns and many unique design approaches have been demonstrated to date. These include 180 • power-dividing baluns using cascaded unit cells [7], [8], [9], power division configurations followed by phase inversion [10], [11], [12], [13], [14], [15], and slot line resonator approaches [16], [17], [18], [19], [20], [21]. Although wide FBWs above 150% have been reported with these techniques, most of the resulting baluns have large physical sizes with footprints ∼0.25 λ 2 g or larger.…”

Design of a Planar Transmission Line Balun Based on Novel Phase Inverter

“…The latter method of phase inversion lies on the conductor exchange of a DSPSL, which is most likely to meet our requirements. However, the performance will deteriorate if the conductors of the DSPSL are directly exchanged without any transitions [23]- [25].…”