Earticle

밀리미터파 위상배열시스템에 위상변환기는 개별안테나의 위상을 조절하는 핵심 부품이다. 본 논문은 손실이 큰 실리콘 웨이퍼의위상변환기에 적용을 위한 설계 기법을 5GHz에서 검증한 내용을 담는다. 0/180도 2-State 위상변환기가 제작되었으며 그것은 2개의2-Stage AMP를 병렬로 구성하였다. 각 State의 Gain을 동일하게 유지하기 위해서 0/180도 Delay 라인을 2-Stage AMP의 각 Stage 중간에 삽입하였다. 통상적으로 AMP를 병렬 연결할 때 Wilkinson Power Combiner/Divider과 같은 수동회로를 추가하지만 실리콘웨이퍼에서는 이것으로 인해 큰손실이 발생할 수 있으므로 생략하고 직접 연결하였다. 제작결과 5GHz에서 12dB이득, 174도 위상차를 확인하여 본 설계 기법을 검증하였다.

A phase shifter is one of the key components that change the phase of an individual antenna in millimeter-wave phased array system. This paper presents a low-loss phase shifter design with two parallel 2-state amplifiers. To get the same gain of 0 〬/180 〬 each state, delay lines are in the middle of each stage of the 2-Stage amplifiers. Normally, when adding AMPs in parallel, a power combiner/divider such as Wilkinson Power Combiner/Divider is added, but they are directly connected because it can cause added losses in silicon wafer. The measured data shows 12dB gain and 174-degree phase difference at 5GHz.

System을 통해 출력되는 신호를 측정할 때 정확한 측정을 방해하는 요소로 잡음이 있다. 이런 신호 측정의 방해 요소인 잡음을 제거 하는 방법 중의 하나로 Lock-in Amp(LIA)가 사용되고 있다. 본 논문에서는 잡음 신호의 제거를 위해 사용 하는 LIA를 제작 하고 특성을 파악 하였으며 RF통신을 이용하여 무선 형태로 제작 하였다. 현재 상용화된 LIA는 프로브를 통한 유선으로 측정신호의 입력을 받게 되지만 본 논문에서 제작된 LIA는 무선신호 형태로 입력 하게 된다. RF통신의 케리어 주파수는 447.9[MHz]로 Digital GMSK 변복조방식을 이용하였다. LIA의 제작은 Dual Phase Sensitive Detecter을 사용하였으며, 주요 구성요소인 Phase Locked Loop, Phase Shifter, Phase Sensitive Detector, Low Pass Filter등의 구조와 특성을 조사하였다.

본 논문은 T 형태의 미엔더 선로를 적용한 브랜치 라인 커플러를 이용하여 고조파가 억압된 소형 저손실의 반사기 형태인 위상 변위기에 대해 제안을 한다. 위상 변위기의 소형 커플러는 22.2×14.9 mm2의 크기를 갖고 있으며, 기존의 브랜치 커플러는 32.6×27.8 mm2의 크기를 나타낸다. 본 논문에서 제안된 위상 변위기는 2.1 GHz의 중심 주파수에서 삽 입손실 0.19~0.28 dB, 그리고 137°의 최대 위상 변위를 보여주고 있다.

In this paper, a compact low-loss reflector-type phase shifter with harmonic suppression using meander T-shaped branch-line coupler is suggested. The compact coupler for the phase shifter has a size of 22.2×14.9 mm2 while a conventional branch coupler has a size of 32.6×27.8 mm2. The phase shifter shows insertion losses of 0.19-0.28 dB at the center frequency of 2.1 GHz, and a measured maximum phase shift of 137°.

본 논문에서는 Ka-대역 수동위상배열탐색기에 적용할 위상 변위기를 설계하고 제작하여 성능을 확인하였다. 수동위상배열안테나에서 배열소자의 위상을 조절하여 전자 빔 조향을 수행하기 위한 핵심 소자인 위상 변위기를 설계하 여 Ka-대역 1GHz 대역폭내에서 삽입손실 1.5dB이하 위상 오차 10°(RMS)이내의 성능을 확인하였다. 실제 제작을 통해 확인된 성능은 배열합성 이론에 기초한 빔패턴 분석에 적용하여 추가적인 분석을 수행하였다. 검증된 위상 변위기의 최 종 성능이 수동위상배열안테나 빔패턴의 성능 및 지향 오차, 각도 정확도에 미치는 영향성을 분석하여 제안된 위상 변위 기 규격의 유효성을 검증하였다.

In this paper, phase shifter has been designed and manufactured to apply to passive phase array seeker for Ka-band and its performance was confirmed. It was designed as a key element for conducting electric beam steering by adjusting the phase of the array element. Insertion loss of less than 1.5dB and phase accuracy of less than 10°(RMS) in operation bandwidth of 1GHz were checked. The performance identified by the actual fabrication was further analyzed by applying the beam pattern analysis based on the array synthesis theory. The effect of the final performamnce of the proven phase shifter on the performance and pointing error and angular accuracy of the passive phase array antenna beam pattern was analyzed. Then, the validation of the proposed phase shifter has been made.

본 논문은 2 GHz대와 12 GHz대에서 동작하는 Phase Shifter를 제안한다. 이것을 위해 비유전율이 2.6인 마이크로 스트립 선로가 사용되었다. 2 GHz대에서 전송선로 위에 비유전율 9인 유전체를 덮어서 주파수 특성이 좋고 선형적인 phase 변화를 가지는 것을 보았다. 12 GHz대에서도 S21의 위상 변화가 유전체 소자의 위치를 변화시킴으로써 약 30。의 우수한 값을 얻을 수 있었다.

This paper presents the characteristics of phase shifter which is operating at 2 GHz band and 12 GHz band. Two types of substrate stick with different dielectric constants are considered in these bands. Dielectric constants of microstrip feed crank line is 2.6. In the case of a small substrate stick with dielectric constant of 9 in the calculation, S21 phase is linearly varied at 1.98 GHz and 2.45 GHz, and variation of the shifting angle is about 20。. The angle of S21 phase shifting at 12 GHz band if calculated about 30。

Nowadays, the study on the ceramic components and modules used in telecommunication system is being performed. Duplexer is the one of the most important components and has the role of dividing Rx and Tx signal. Duplexer including the FBAR is being done vigorously LTCC is used for package like SAW package, duplexer package. In our research, LTCC material is used for FBAR duplexer package and photo-lithography for the fine line phase shifter. The good characteristics, low loss and good isolation, of duplexer is obtained by the fine line phase shifter having high characteristic impedance of stripline.

This paper proposes a CMOS 6-bit phase shifter with low RMS phase and amplitude errors for an X-band phased array antenna. The phase shifter combines a switched-path topology for coarse phase states and a switch-filter topology for fine phase states. The coarse phase shifter is composed of phase shifting elements, single-pole double-throw (SPDT), and double-pole double-throw (DPDT) switches. The fine phase shifter uses a switched LC filter. The phase coverage is $354.35^{\circ}$ with an LSB of $5.625^{\circ}$. The RMS phase error is < $6^{\circ}$ and the RMS amplitude error is < 0.45 dB at 8-12 GHz. The measured insertion loss is < 15 dB, and the return losses for input and output are > 13 dB at 8-12 GHz. The input P1dB of the phase shifter achieves > 11 dBm at 8-12 GHz. The current consumption is zero with a 1.2-V supply voltage. The chip size is $1.46{\times}0.83mm^2$, including pads.

This paper proposes a frequency reconfigurable dual-band passive 360° reflection-type phase shifter (RTPS) for fifth-generation (5G) applications. The proposed phase shifter provides a full 360° phase shift range in multiple 5G new radio (NR) communication bands?n261 (27.5?28.35 GHz) and n260 (37?40 GHz)?using a transformer-based switchable inductor. The proposed transformer-based switchable inductor allows the operating frequency bands to be changed for achieving maximum phase shift range. Consequently, the proposed RPTS achieves a full 360° phase shift range with average insertion losses of 7.65 ± 2.08 and 7.03 ± 0.15 dB at 28 and 39 GHz, respectively. To the best of our knowledge, the proposed RTPS is the first dual-band RTPS to achieve a 360° phase shift in 5G NR FR2 applications.

A parallel-feeding AC traction power system increases the power supply capacity and decreases voltage fluctuations, but the circulating power flow caused by the phase difference between the traction substations prevents the system from being widely used. A circuit analysis shows that the circulating power flow increases almost linearly as the phase difference increases, which adds extra load to the system and results in increased power dissipation and load unbalance. In this paper, we suggest a phase shifter for the parallel-feeding AC traction power system. The phase shifter regulates the phase difference and the circulating power flow by injecting quadrature voltage which can be obtained directly from the Scott-connection transformer in the traction substation. A case study involving the phase shifter applied to the traction power system of a Korean high-speed rail system shows that a three-level phase shifter can prevent circulating power flow while the phase difference between substations increases up to 12 degrees, mitigate the load unbalance, and reduce power dissipation.

This paper introduces a reflective-type phase shifter (RTPS) and a defected ground patch antenna design for configuring a 4-bit 250 GHz on-chip beamforming system using a SiGe HBT device. The patch antenna is designed to operate at 250 GHz, with a defected ground structure implemented to address the issue of narrow bandwidth. Four ground slots, each sized 50 x 121 ? m2, are fabricated, and measurement results show that the patch antenna operates within the 240-257 GHz band. The RTPS is designed using a 90o hybrid coupler and variable loads using varactors. The 90o hybrid coupler is made compact by overlapping two adjacent 50-? quarter-wavelength lines and forming a slot on the ground plane. The varactor is based on a diode-connected SiGe HBT device, and its size is selected as the largest available 7.2 mm in length to maximize the capacitance variation with the bias input. Two RTPS unit cells are connected in series to achieve a 360o phase shift, and the measurement results demonstrate a 4-bit phase shift.

A sandwich structure of dielectric material and air gap inside a rectangular waveguide is proposed as a fast electrically tunable low-loss phase shifter. As the dielectric material is shifted up and down by piezoelectric actuator and, thereby, the thickness of air gap is changed, the effective dielectric constant of the sandwich structure is varied. Phase shifters based on the sandwich structure with different dielectric materials showed phase shift of $20{\sim}200^{\circ}/cm$ at X-band as the thickness of air gap varied up to $30{\mu}m$. The idea can be extended toward low-loss millimeter wave phase shifters since modem microwave ceramics have been developed to show very low dielectric loss$(tan\;{\delta}{\sim}10^{-4})$.

A method of wideband constant phase control is proposed. This can be applied to reflection type phase shifter with p-i-n diode. Using the proposed method, a microwave phase network which consists of a transmission line and reactive circuit element is suggested. By determining theproper values of design parameters, the desired wideband constant phase with different specification can easily be designed. Also, using the proposed method, the parameters variation, and 1.1 dB of insertion loss in the range of 12% bandwidth.

This paper presents a 300-GHz phase shifter and a fundamental high-power VCO designed using a 250-nm InP double heterojunction bipolar transistor (DHBT) technology. The phase shifter employs a 180° reflection-type phase shifter (RTPS) and a 1-bit 180° active switched-type phase shifter (STPS) to achieve a 360° phase shift range. The STPS includes an active single-pole double-throw (SPDT) switch for compensating insertion loss of the passive components and providing gain. The simulation shows that the phase shifter achieves a full 360° phase shift over the frequency range from 220 to 320 GHz. The peak average gain is 1.3 dB at 285 GHz and the 3-dB bandwidth is 50 GHz. In addition, the common-base cross-coupled VCO core employs a coupled-line feedback to minimize the loss caused by via interconnections. To further increase the output power, the differential signal from the output buffer is combined by a slotline power combiner. By modeling the microstrip-to-slotline transition, the equivalent circuit and impedance matching of the combiner is analyzed. The simulated output power is 8.4 dBm at 300 GHz and the dc power consumption is 90 mW. This leads to a peak dc-to-RF efficiency of 7.2 %. The VCO exhibits a simulated frequency tuning range of 20 GHz (300?320-GHz).