SIMULATION OF CO-PLANAR WAVEGUIDE LIQUID CRYSTAL BASED PHASE SHIFTER

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Nasser A ALQuaiti ◽  
Noor Asniza Murad
Keyword(s):  
Liquid Crystal ◽  
Phase Shift ◽  
Phase Shifter ◽  
Low Cost ◽  
Continuous Phase ◽  
Phase Shifting ◽  
Telecommunication System ◽  
Liquid Crystal Material ◽  
Compact Size ◽  
5Cb Liquid Crystal

This paper discussed the design and performances of a liquid crystal phase shifter that can be used in tuning devices. Tuning devices growth with the demand in the emerging in telecommunication system. Tuning devices with smooth continuous phase shifting at low cost and compact size would be an advantage. This paper proposed a phase shifter using 5CB liquid crystal material. The advantages of using the material is the smoothness and continuity of the transitions in the phase shift. It is done by having a structure with cavity filled with the liquid crystal and applied with certain voltage that can be changed. The changes in voltage would change the applied electric field, and thus would change the permittivity of the material. The changes would affect the wave propagation and thus contribute to the phase shifting. The performance of the phase shifter was tested by means of simulation using CST Suite 2014 software. The results show that the higher the frequency, the higher the phase shift would occur. The highest FoM achieved is 68 (deg/dB) at 8 GHz. A phase shifter with smooth and continuous phase shift can be used as the feeding network in an array scanning antennas systems.

Application of Ferroelectrics in Low-Cost Microwave Phased-Array Antennas

2002 ◽  
Vol 720 ◽  
Author(s):  
J. B. L. Rao ◽  
D. P. Patel ◽  
P. K. Park ◽  
T. K. Dougherty ◽  
J. A. Zelik ◽  
...  
Keyword(s):  
Phase Shifter ◽  
Phased Array ◽  
Low Cost ◽  
Bulk Phase ◽  
Phase Shifting ◽  
Phased Array Antenna ◽  
Beam Scanning ◽  
Phased Array Antennas ◽  
Array Antennas ◽  
Radiating Element

AbstractA novel, low-cost, phased-array antenna that uniquely incorporates bulk phase shifting using voltage-tunable dielectric (VTD) material is presented. The array does not contain an individual phase shifter at each radiating element. This paper presents the antenna concept and describes how it can be used as a low-cost phased array. The VTDs that are used in this antenna are described. The measured antenna patterns of a prototype phased array demonstrating electronic beam scanning at 10 GHz are also presented.

Phase Shift Near Natural Frequencies of Non Linear Rods

2001 ◽  
Author(s):  
Ioannis T. Georgiou
Keyword(s):  
Phase Shift ◽  
Natural Frequencies ◽  
Basin Of Attraction ◽  
Continuous Phase ◽  
Phase Shifting ◽  
Periodic Attractor ◽  
Jump Frequency ◽  
Stable Attractor ◽  
Configuration Changes ◽  
Transient And Steady State

Abstract We study the transient and steady state dynamics of a special class of motions of forced planar rods with exact geometric nonlinearity. The attractors of these motions are separated by a finite jump at a critical forcing frequency in an attractor diagram of the undistorted configuration generated by a quasi-static frequency sweep at fixed forcing amplitude. As the frequency of the forcing passes through this critical or jump frequency, the motion (trajectory) of the undistorted configuration changes basin of attraction. For forcing frequency slightly greater than the jump frequency, the response trajectories of the undistorted configuration pass near an unstable periodic attractor and undergo continuous phase shift while approaching a stable attractor. For forcing frequency slightly smaller than the jump frequency, the response trajectories of the undistorted configuration pass near the same unstable attractor and undergo no net phase angle when landing on the stable attractor that attracts them. The phase-shifting property reveals that the frequncy at which the jump occurs is indeed a natural frequncy of the nonlinear rod.

scholarly journals 26 GHz phase shifters for multi-beam nolen matrix towards fifth generation (5G) technology

2019 ◽  
Vol 8 (3) ◽  
pp. 1028-1035
Author(s):  
Norhudah Seman ◽  
Nazleen Syahira Mohd Suhaimi ◽  
Tien Han Chua
Keyword(s):  
Dielectric Constant ◽  
Microstrip Line ◽  
Return Loss ◽  
Phase Shifter ◽  
Low Cost ◽  
Phase Shifters ◽  
Substrate Thickness ◽  
Fifth Generation ◽  
Compact Size ◽  
Better Than

This paper presents the designs of phase shifters for multi-beam Nolen matrix towards the fifth generation (5G) technology at 26 GHz. The low-cost, lightweight and compact size 0° and 45° loaded stubs and chamfered 90°, 135° and 180° Schiffman phase shifters are proposed at 26 GHz. An edge at a corner of the 50 Ω microstrip line Schiffman phase shifter is chamfered to reduce the excess capacitance and unwanted reflection. However, the Schiffman phase shifter topology is not relevant to be applied for the phase shifter less than 45° as it needs very small arc bending at 26 GHz. The stubs are loaded to the phase shifter in order to obtain electrical lengths, which are less than 45°. The proposed phase shifters provide return loss better than 10 dB, insertion loss of -0.97 dB and phase difference imbalance of ± 4.04° between 25.75GHz and 26.25 GHz. The Rogers RT/duroid 5880 substrate with dielectric constant of 2.2 and substrate thickness of 0.254 mm is implemented in the designs.

scholarly journals Design of 3-Bit Digital RF Phase Shifter for Wireless Communication

2019 ◽  
Vol 8 (2) ◽  
pp. 2292-2296
Keyword(s):  
Phase Shift ◽  
Wireless Communication ◽  
Transmission Line ◽  
Phase Shifter ◽  
Phased Array ◽  
Low Cost ◽  
Phase Shifters ◽  
Phased Array Antenna ◽  
Radio System ◽  
Digital Phase

In this paper, a 3-bit digital phase shifter based on switched transmission line technique using coplanar waveguide is proposed. The design has the resonant frequency of 10 GHz which can be used in wireless communication applictaions. Recent developments in radio frequency components development has raised as a significant way for constructing low loss phase shifters. MEMS phase shifters whose insertion loss is low and high isolation uses minimum power. This helps to bring low cost and light weighted phased array antennas. The transmission line length and wavelength decides the characteristics of phase shift. The phase shifter design consists of coplanar waveguides having center conductor width of 100µm and the gap of 14 µm on a FR-4 epoxy substrate with thickness of 1.6mm. The design is simulated using ADS to yield phase shift of 45, 90 and 180. The benefits of digital phase shifters include achieving flat phase over a wide bandwidth as well as having higher power handling and linearity with uniform performance. The phase shifters are used in different fields which includes microwave devices, feeder of radio system, phased array antenna, coherent radio system, etc.

Progress of liquid crystal adaptive optics for applications in ground-based telescopes

2020 ◽  
Vol 494 (3) ◽  
pp. 3536-3540
Author(s):  
Xingyun Zhang ◽  
Zhaoliang Cao ◽  
Quanquan Mu ◽  
Dayu Li ◽  
Zenghui Peng ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Liquid Crystal ◽  
Adaptive Optics ◽  
Low Cost ◽  
Response Speed ◽  
Open Loop ◽  
Loop Control ◽  
Compact Size ◽  
Control Scheme ◽  
Resolution Imaging

ABSTRACT Liquid crystal (LC) adaptive optics systems (AOS) can potentially be used in ground-based large aperture telescopes, because of their high spatial resolution, low cost and compact size. However, their disadvantages, such as low energy efficiency and slow response speed, still hinder their application. In this paper, we demonstrate solutions to these problems. With newly synthesized fast nematic LC material and using an overdriving technique, the response time of a LC wavefront corrector was reduced to 0.75 ms. Under an open-loop control scheme, a novel optical system was designed to improve the energy efficiency of LC AOS. With those problems resolved, a LC AOS was built for a 1.23-m telescope. This system has a disturbance rejection bandwidth of 80 Hz, and could fully use the energy of 400–900 nm wavebands. Observation results showed that the diffraction limit resolution imaging of the telescope could be obtained after correction, which indicates that the LC AOS is ready to be used in ground-based telescopes for visible waveband imaging.

Sign in / Sign up

Export Citation Format

Share Document