Topic
Return loss
About: Return loss is a research topic. Over the lifetime, 11090 publications have been published within this topic receiving 97603 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a 400 GHz broadband multi-branch waveguide hybrid coupler is designed, but it is very difficult to fabricate and it is also measured in order to release the processing difficulty.
Abstract: Terahertz technology is a hotspot in the current academic research. In this study, a 400 GHz broadband multi-branch waveguide hybrid coupler is designed, but it is very difficult to fabricate. In order to release the processing difficulty, a modified five-branch hybrid coupler has also been designed, fabricated and measured. The hybrid coupler consists of five modified branches and has been optimised to a great performance, which increases the operation bandwidth. Compared to the traditional five-branch hybrid coupler design, this structure has a wider operation bandwidth and the bandwidth is almost the same as traditional seven-branch hybrid coupler. Based on this model, the performance of the coupler is optimised by HFSS software. The measurement results show good performance that >18 dB return loss (S
11
) and isolation (S
23
), 90° ± 2° phase difference and 0.3 dB amplitude imbalance are obtained in the frequency range of 380-460 GHz, agreeing well with the simulation results.
50 citations
TL;DR: In this article, a methodology for the design of miniature lumped element components embedded in a low-temperature co-fired ceramic (LTCC) package is presented, from initial schematic design, through individual element design, to complete device optimization.
Abstract: We present a novel methodology for the design of miniature lumped element components embedded in a low-temperature co-fired ceramic (LTCC) package. The entire process, from initial schematic design, through individual element design, to complete device optimization is discussed. The design and fabrication of novel miniature lumped element LTCC filters is used to validate the proposed methodology. Commercial software tools are used to accurately model and simulate all aspects of the devices to ensure design success. In addition, the filters occupy only 0.03 lambda times 0.05 lambda times 0.004 lambda of a conventional low-permittivity LTCC substrate, which is among the smallest sizes reported. An advantage of these filters is that they use a true third-order topology with three multilayer L-C resonators, leading to superior stopband performance. For the first time, measured results are shown for two new bandpass filters targeted for global positioning system applications. Measured results are in good agreement with the simulations and show an insertion loss of 2.8 dB and a return loss of 21.3 dB at the center frequency of 1.64 GHz.
50 citations
TL;DR: In this paper, a novel metamaterial broadband microstrip balun design is proposed, where the odd mode is allowed while the even mode is rejected, and a virtual ground is formed between the symmetric plane.
Abstract: A novel metamaterial broadband microstrip balun design is proposed. The broadband balun consists of a pair of identical metamaterial transmission lines. In the odd mode, a virtual ground is formed between the symmetric plane. The odd mode is allowed while the even mode is rejected. No vias are required to realize the shunt inductors of the metamaterial lines, and no power divider is used. Baluns with good performance can be achieved. In this letter, two baluns are fabricated and measured. For the balun with seven units, the output amplitude difference is less than 0.7 dB, and the differential phase is 181deg plusmn 3deg from 1.6 to 3.6 GHz, while the input return loss is greater than 10 dB.
50 citations
TL;DR: In this article, a new approach to designing a handset antenna for satellite applications is reported, based on precise control of the phasing between two bifilar helices, giving accurate resonant frequency position and radiation pattern volute.
Abstract: A new approach to designing a handset antenna for satellite applications is reported. It is based on precise control of the phasing between two bifilar helices, giving accurate resonant frequency position and radiation pattern volute. Results show an antenna with a gain of -2 dBi, 19 dB discrimination between the right and left hand circular polarisations and an axial ratio less than 1 dB. The front-to-back ratio is 24 dB. A return loss of 14.6 dB is also measured.
50 citations
TL;DR: In this article, a planar wideband wide-angle polarization-free reflectionless MSL and three feeding sources of ±45° polarized cross-dipole antennas are proposed for multibeam base station operating over the band of 1.71-2.2 GHz.
Abstract: A compact wideband wide-angle polarization-free metasurface lens (MSL) antenna array is proposed for a multibeam base station operating over the band of 1.71–2.2 GHz. The MSL element comprises of a planar wideband wide-angle polarization-free reflectionless MSL and three feeding sources of ±45° polarized cross-dipole antennas. With the shared lens aperture, the antenna achieves the three beams in the directions of 0° and ±30° in a horizontal plane. A five-layer patch-based metasurface loaded with metal poles are introduced to achieve consistent performance for wide-angle response. To reduce spillover loss, the feeding antennas are loaded with a metasurface and four directors for narrow beamwidth and low profile. With the optimized feeding antennas and MSL, a section of array with $1\,\,\times \,\,4$ MSL elements is prototyped for validation. The measured results show that an impedance bandwidth for return loss ≥ 10 dB is 1.63–2.24 GHz with the isolation larger than 22.3 dB. The measured gain ranges for 0° and 30° beams are 11.8–13.5 and 10–12.2 dBi with the sidelobe levels less than −22.6 and −13.6 dB, respectively.
50 citations