• Journal of electromagnetic engineering and science
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• v.9 no.3
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• pp.159-163
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• 2009

This paper presents the design and implementation of Q-band MMIC phase shifters using InGaAs PIN diodes. The topology using a thin-film microstrip line(TFMS) has been proposed to achieve the desired phase-shift as well as good loss characteristics. Five single-bit MMIC phase shifters have been implemented by using a developed BCB(benzocyclobutene)-based multi-layer fabrication technology. The developed phase shifters have less than 3.4 dB of insertion loss and better than 11 dB of input and output return loss in the frequency range of 43 to 47 GHz. To the authors' knowledge, this is the first demonstration of high-performance InGaAs PIN diode-based MMIC phase shifters operating at Q-band frequencies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.1 s.104
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• pp.1-7
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• 2006

New phase shifters with higher phase shift values are presented using defected ground structures(DGSs). The varactor diodes are mounted on DGSs of termination loads to control the large phase variation of the DGS at resonance. Two types of phase shifters are implemented with a branch-line and a coupled line hybrid. The experimental results of the proposed phase shifters show $135\%$ and $221\%$ increases in maximum phase shills, respectively, compared with those of conventional ones.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.3
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• pp.371-375
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• 2014

In this paper, we compared the performances of the Right Handed Transmission Line (RHTL) and the Left Handed Transmission Line (LHTL) phase shifters as a frequency translator. Unlike other phase shifters, both phase shifters show a $0^{\circ}-360^{\circ}$ phase variation for a broadband frequency and compact in size which are ideal to use as a frequency translator. For the performance comparison, we fabricated both a RHTL and a LHTL phase shifter to cover 1.5 GHz - 2.4 GHz range with the whole $360^{\circ}$ phase variation. For the frequency range, a LHTL based frequency translator showed a much better performance whose Spurious Free Dynamic Range (SFDR) is 4dB - 17dB higher than the RHTL based frequency translator when the sawtooth modulation freqncy is 11 kHz. This is due to the linear phase-voltage variation of LHTL phase shifter. Furthermore, the LHTL phase shifter shows a less insertion loss and a insertion loss variation than the RHTL phase shifter. Overall, the LHTL based frequency translator outperformed RHTL based freqency translator.

• Journal of electromagnetic engineering and science
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• v.3 no.1
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• pp.62-66
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• 2003

Novel coupled line phase shifters and its equivalent phase delay line for compact broadband phased array antennas are proposed. These phase control circuits are designed to be less complex, small size and to use a less number of active devices. The phase shifter is able to control a 120$^{\circ}$ phase shift continuously, and the phase delay line for a reference phase has a fixed 60$^{\circ}$ shifted phase. Both have the low phase error of less than $\pm$3.5$^{\circ}$ and the low gain variations of less than 1 ㏈ within the 300 MHz bandwidth. These proposed circuits are adequate to form the efficient beam-forming networks with compactness, broadband, less complexity, and low cost.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3205-3214
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• 1996

In this paper, the microstrip phased array antennas with coupling-slots for the base station of mobile communication is proposed and anlyzed with accurate analysis method which is based on both reciprocity principle and full-wave analysis. The basis functions used for the numerical analysis are determined depending upon the accuracy, convergence properties of the solution, and the computation time. The patch uses 3 EB mode and the slot uses IPWS mode. The designed phased array antenna has 8 slot-coupled microstrip patch array elements and the beam scanning capability is obtained by using the 4-bit PIN-diode phase shifters as switching devices which are consisted of the loaded line phase shifters for 30.deg. and 60.deg. and the reflection type phase shifters for 90.deg. and 180.deg. repectively. The 4-bits phase shifters which aremade by connecting each phase shifter have about 2.deg.-3.deg. phase errors and their insertion loss are about 3dB for each phase state. The fabricated 8-element phased array antenna with 4-bits phase shifters provides 12.deg.-14.deg. beamwidths depending on the scanning angle and is capable of scanning its beam to .+-.45.deg. with 9.deg. intervals, and the gain 12dBi. The overall results show that the slot-coupled phased array antenna has great advantages of wideband, high gain and reduced spurious radiation. Also, the antenna can be made small and thin. Furthermore, the scanning property of this antenna allows for its application in several areas, such as mobile communication system and PCS.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1145-1151
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• 1989

New method to calculate the characteristics of the dominant and higher order modes of waveguide latching phase shifters are presented. Due to the tensor permeability, E and H fields inside the ferrite are expanded in terms of the LSE and LSM eigenmodes of the dielectric-slab-loaded waveguide. The equivalent coupled transmission line equations on the transverse plane are derived to obtain the dispersion characteristics and the E and H field distributions. Numerical results at X-band are compared with those published previously. The derived field distributions can be used to suppress the higher order modes of the latching phase shifters, so that the phase shift from the dominant mode only contributes the performance of the phase shifters.

• ETRI Journal
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• v.26 no.4
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• pp.307-314
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• 2004

The application of a discrete pseudomorphic high electron mobility transistor (p-HEMT) as a grounded switch allows for the development of low cost phase shifters and phase modulators operating in a Ku band. This fills the gap in the development of phase control devices comprising p-i-n diodes and microwave monolithic integrated circuits (MMICs). This paper describes a discrete p-HEMT characterization and modeling in switching mode as well as the development of a low-cost four-bit phase shifter and direct quadrature phase shift keying (QPSK) modulator. The developed devices operate in a Ku band with parameters comparable to commercially available MMIC counterparts. Both of them are CMOS compatible and have no power consumption. The parameters of the QPSK modulator are very close to the requirements of available standards for satellite earth stations.

• ETRI Journal
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• v.27 no.6
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• pp.677-684
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• 2005

A phased array antenna was fabricated using four-element ferroelectric phase shifters with a coplanar waveguide (CPW) transmission line structure based on a $Ba_{0.6}Sr_{0.4}TiO_3(BST)/MgO$ structure. Epitaxial BST films were deposited on MgO (001) substrates by pulsed laser deposition. To attain the large differential phase shift and small losses for a ferroelectric CPW phase shifter, an impedance-matching-part adding technique between the effective transmission line and connecting cable was used. The return loss and insertion loss for this techniqueadapted BST CPW device were improved with respect to those for a normal BST CPW device. For an X-band phased array antenna system consisting of ferroelectric BST CPW phase shifters, power divider, dc block, patch antenna, and programmed dc power, the steering beam could be tilted by $15^{\circ}$ in either direction.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.345-349
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• 2000

A microstrip polarized 8${\times}$2 linear phased array antenna with four 4-bit phase shifters is designed at 10 GHz. The 180$^{\circ}$and 90$^{\circ}$ sections of the phase shifter are of the switched line type, and the rests are of the loaded line type. A 2${\times}$2 sequential sub-array is adopted for a broad axial ratio bandwidth. The construction of the array antenna is of the tile type placing the phase shifters on the same layer containing the feed network. The element spacing is chosen to be 0.45λ$\sub$0/ to exclude the grating lobe. Measurement results show a gain 9.69 dB at broadside and 8.3 dB at the beam-tilt angle of 16$^{\circ}$ by imposing a progressive phase of 90$^{\circ}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.6
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• pp.1116-1121
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• 2001

Phase shifter has been used as a means of power-flow control and for transient stability improvement in AC transmission system. Until now, phase shifters have been based on an injection transformer. Conventional phase shifters with tap changers require regular maintenance and allow only step-like control of the phase angle. This paper propose a three-phase phase shifter using PWM AC/AC converter, which can improve system response and control stability in the applications. This paper deals with the circuit topology, operating principle so that the features of the phase shifter will be shown through computer simulation, especially using PSIM software.