Compact coplanar waveguide power splitter with filtering capability based on slow‐wave structures

Abstract

A compact coplanar waveguide (CPW) power splitter with filtering capability is presented in this paper. The splitter consists of a pair of 70.71 Ω impedance inverters implemented by means of inductively and capacitively loaded slow‐wave structures. Such slow‐wave structures efficiently shorten the length of the inverters, thereby providing substantial size reduction to the power splitter. The filtering functionality is due to the Bragg effect, related to periodicity. The proposed splitter, designed to be functional at 1 GHz, exhibits good performance at that frequency, with measured return loss of 20.6 dB and insertion loss of 3.15 dB and 3.23 dB at the output ports. Moreover, the suppression level at the first, second and third harmonic frequency is better than 12.4 dB, 34.6 dB and 24.7 dB, respectively. As compared to the length of the ordinary inverters, the length of the constitutive slow‐wave impedance is reduced by a factor of two.

Miniaturisation of branch line couplers with a compact transmission line topology based on coupled line section

“…[4,10] but not in terms of harmonic suppression. Although, in [4,10] good harmonics suppression is obtained it required more simulation time to optimise the design parameters in order to obtain the desired frequency response. The proposed design maintains a good balance between size reduction, harmonic suppression, and design complexity.…”

“…1c and d. The evenmode input admittance (Y even ) seen from port 1 is obtained by (3) using (1) and (2) for the proposed line and for the conventional line by (4). The even-mode admittance of a coupled line is obtained from (5) by solving (3) and 4Y e ′ = jY a tan θ a (1)…”

“…Nowadays communication industry motivates the researchers to design microwave components that reduce the cost of the overall system. Branch line coupler (BLC) is one of the most important microwave components, which is used in balance mixer, power divider/combiner, and phase shifter [1][2][3][4]. However, BLC suffers from a larger size specifically at lower frequency due to quarter wavelength lines.…”