A compact microstrip rat-race hybrid with a 50% bandwidth employing space-filling curves is
reported in this letter. The footprint of the proposed design occupies 31% of the area of the …

A broadband printed quadrifilar helical antenna employing a novel compact feeding circuit is
proposed in this paper. This antenna presents an excellent axial ratio over a wide …

This paper presents a novel design method of rat-race couplers with tunable frequency. The
port equivalent impedances of a reciprocity four-port network being matched and isolated …

With the rapid development of modern wireless communication systems, the desirable
miniaturization, multifunctionality strong harmonic suppression, and enhanced bandwidth of …

Design of broadband rat-race couplers with the use of a shorted coupled-line section and
impedance transformers has been comprehensively investigated. A broadband rat-race …

A transmission line (TL) loaded, compact, ultrawideband (UWB) square slot antenna is
proposed in this letter. The square slot is a microstrip line fed and loaded with an array of …

In this paper, a compact filtering rat-race coupler implemented in low-temperature co-fired
ceramic (LTCC) technology is presented. In order to reduce the dimensions, the schematic …

Wideband coupled-line ring hybrids are presented for high power-division ratios. For this, an
equivalent circuit to make the characteristic impedance of a transmission-line section lower …

The design, development and fabrication of compact microstrip ring-hybrid couplers are
presented in the present paper. In order to obtain miniaturization, λ/4 microstrip lines in a …

A circularly polarized antenna array design comprising of a feed network that splits an input
signal into four orthogonal (0°, 90°, 180°, and 270°) phased signals with equal magnitudes …