scholarly journals Design of composite right/left-handed transmission line for phase shifter of multi-band base station antenna

2018 ◽  
Vol 5 ◽  
pp. 12
Author(s):  
Naobumi Michishita ◽  
Yoshihide Yamada ◽  
Keizo Cho
Keyword(s):  
Phase Shift ◽  
Transmission Line ◽  
Phase Shifter ◽  
Vertical Plane ◽  
Equivalent Circuit Model ◽  
Base Station ◽  
Unit Cell ◽  
Operating Frequency ◽  
Left Handed ◽  
Multi Band

In multi-band base station antennas, interference toward neighboring cells at low operating frequency in-creases since tilting angle is frequency-independent and beamwidth in the vertical plane increases as de-creasing the operating frequency. In this paper, the realization of the different phase shifts at each frequency is proposed by using the dispersion relation of the composite right/left-handed transmission line. The feasi-bility of the phase shift is clarified by using equivalent circuit model of the unit cell. Next, the dispersion and Bloch impedance of the actual configuration of the unit cell are designed. The inverse phase shift at each frequency is verified experimentally.

scholarly journals Bandwidth and gain enhancement of composite right left handed metamaterial transmission line planar antenna employing a non foster impedance matching circuit board

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Ayman A. Althuwayb ◽  
Leyre Azpilicueta ◽  
Naser Ojaroudi Parchin ◽  
...  
Keyword(s):  
Transmission Line ◽  
Impedance Matching ◽  
Circuit Board ◽  
Operating Frequency ◽  
Planar Antenna ◽  
Effective Technique ◽  
Input Capacitance ◽  
Gain Enhancement ◽  
Microstrip Patch ◽  
Left Handed

AbstractThe paper demonstrates an effective technique to significantly enhance the bandwidth and radiation gain of an otherwise narrowband composite right/left-handed transmission-line (CRLH-TL) antenna using a non-Foster impedance matching circuit (NF-IMC) without affecting the antenna’s stability. This is achieved by using the negative reactance of the NF-IMC to counteract the input capacitance of the antenna. Series capacitance of the CRLH-TL unit-cell is created by etching a dielectric spiral slot inside a rectangular microstrip patch that is grounded through a spiraled microstrip inductance. The overall size of the antenna, including the NF-IMC at its lowest operating frequency is 0.335λ0 × 0.137λ0 × 0.003λ0, where λ0 is the free-space wavelength at 1.4 GHz. The performance of the antenna was verified through actual measurements. The stable bandwidth of the antenna for |S11|≤ − 18 dB is greater than 1 GHz (1.4–2.45 GHz), which is significantly wider than the CRLH-TL antenna without the proposed impedance matching circuit. In addition, with the proposed technique the measured radiation gain and efficiency of the antenna are increased on average by 3.2 dBi and 31.5% over the operating frequency band.

scholarly journals Four-Port Dual-Mode Diplexer with High Signal Isolation

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Jessada Konpang ◽  
Natchayathorn Wattikornsirikul
Keyword(s):  
Phase Shift ◽  
Transmission Line ◽  
Phase Shifter ◽  
High Signal ◽  
Dual Mode ◽  
High Isolation ◽  
Centre Frequency ◽  
Phase Cancellation ◽  
Signal Isolation

An ease of four-port dual-mode diplexer with high signal isolation is presented. A compact dual-mode diplexer with high signal isolation between the Rx and Tx modules is achievable by only using one resonator filter topology. Two back-to-back dual-mode diplexers have a 180° phase shift in one branch. The high isolation can be achieved by amplitude and phase cancellation technique. The delayed transmission line can be easily achieved by the phase shifter. The simulated and measured four-port dual-mode diplexers are designed at the centre frequency of Rx/Tx at 1.95 GHz and 2.14 GHz, respectively. The measured results of Rx/Tx dual-mode diplexer devices are presented with 47.1 dB Rx/Tx isolation. This four-port dual-mode diplexer achieves the isolation (S32) of more than 24.1 dB when compared with the conventional three-port dual-mode diplexer structure.

Broadband Tunable Third-Order IMD Cancellation Using Left-Handed Transmission-Line-Based Phase Shifter

2015 ◽  
Vol 25 (7) ◽  
pp. 478-480 ◽  
Author(s):  
Hongwoo Park ◽  
Hyoungsuk Yoo ◽  
Sungtek Kahng ◽  
Hongjoon Kim
Keyword(s):  
Transmission Line ◽  
Phase Shifter ◽  
Third Order ◽  
Left Handed
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