Return loss

About: Return loss is a research topic. Over the lifetime, 11090 publications have been published within this topic receiving 97603 citations.

Three-Pole Tunable Filters With Constant Bandwidth Using Mixed Combline and Split-Ring Resonators

Abstract: A novel three-pole tunable bandpass filter using mixed varactor-tuned combline and split-ring resonators is proposed in this letter. A tuning range of 1.1-1.88 GHz (70.9%) with an almost constant 3 dB absolute bandwidth of 90 ±8 MHz (7.4%-4.4% fractional bandwidth) is demonstrated. The filter shows its insertion loss varying from 6.8 dB to 4.3 dB and return loss better than 13.5 dB within the tuning range. The rejection levels at both the lower and upper stopbands are > 30 dB. The measured results show good agreement with the simulated ones.

Miniaturised artificial magnetic conductor design using lumped reactive components

Abstract: A miniaturised artificial magnetic conductor (AMC) using lumped capacitors is introduced. Simulated reflection phase data is presented, which proposes a unit cell periodicity of lambda/49, with a + 90deg bandwidth of 10%. Simulated and measured return loss and radiation patterns are presented, which show that the miniaturised AMC provides < - 10 dB return loss at resonance and 10 dB of back radiation reduction.

Micromachined Millimeter-Wave Rectangular-Coaxial Branch-Line Coupler With Enhanced Bandwidth

Abstract: Wideband millimeter-wave branch-line couplers have been demonstrated using micromachined air-filled rectangular-coaxial lines supported by quarter-wavelength stubs. The coaxial lines are constructed by bonding five layers of gold-plated silicon or SU8 slices. The measured coupler shows an insertion loss of 3.2-4.0 dB in the coupled and thru ports between the frequencies 31.3-47.6 GHz. The isolation is better than 12.8 dB, and the return loss less than -10 dB. In addition to providing support, the stubs enhance bandwidth when properly placed.

Compact UWB Bandpass Filter Using

Abstract: A compact microstrip-line ultra-wideband (UWB) bandpass filter (BPF) using the proposed stub-loaded multiple- mode resonator (MMR) is presented. This MMR is formed by loading three open-ended stubs in shunt to a simple stepped- impedance resonator in center and two symmetrical locations, respectively. By properly adjusting the lengths of these stubs, the first four resonant modes of this MMR can be evenly allocated within the 3.1-to-10.6 GHz UWB band while the fifth resonant frequency is raised above 15.0 GHz. It results in the formulation of a novel UWB BPF with compact-size and widened upper-stopband by incorporating this MMR with two interdigital parallel-coupled feed lines. Simulated and measured results are found in good agreement with each other, showing improved UWB bandpass behaviors with the insertion loss lower than 0.8 dB, return loss higher than 14.3 dB, and maximum group delay variation less than 0.64 ns in the realized UWB passband.

Analysis of broadband slotted microstrip patch antenna

Abstract: In this paper, a novel multiple slot microstrip patch antenna with enhanced bandwidth is presented. The design adopts contemporary techniques namely; probe feeding, inverted patch structure and multiple slotted patch. The composite effect of integrating these techniques and by introducing the novel multiple shaped patch, offer a low profile, wide bandwidth, high gain and compact antenna element. The proposed patch has a compact dimension of 0.707 lambda0 times 0.354 lambda0 (where lambda0 is the guided wavelength of the center operation frequency). With the proposed concept, an antenna prototype is simulated and analyzed. The proposed antenna achieves a fractional bandwidth of 27.15% (1.91 to 2.51 GHz) at 10 dB return loss while maintaining a maximum gain of 10.5 dBi. The design is suitable for array applications especially for base station.