Broadband Phase Shifter Research Articles

Design of broadband phase shifters with low phase deviation

Design of broadband phase shifters with low phase deviation

A novel wideband phase shifter on coupled microstrip line

AbstractIn this paper, a new 180° broadband phase shifter with coupled microstrip line with enhanced coupling by etched slots is proposed, which uses the energy coupling between the parallel‐coupled microstrip lines on the upper layer of the dielectric substrate and the etched rectangular slots (RS) structure on the bottom floor to circumvent the problem for achieving wide operating broadband and low insertion loss with compact size and simple structure. First, the main line and the reference line of the proposed phase shifter are composed of two parallel coupled lines and a uniform transmission line, respectively. Then, its working mechanism is described. Afterward, the phase shifter introduced an RS structure to increase the coupling strength, achieving a broadband of 69.7% and very low insertion loss (0.09 dB) with a phase shift of 180 ± 5°. Finally, a prototype 180° phase shifter with a center frequency of 3.0 GHz was designed, fabricated, and measured, and the measured results are good in agreement with the simulated ones.

A gap waveguide-based mechanically reconfigurable phase shifter for high-power Ku-band applications

This paper presents a novel design of a low-loss, reconfigurable broadband phase shifter based on groove gap waveguide (GGW) technology. The proposed phase shifter consists of a folded GGW and three bends with a few pins forming the GGW and one bend attached to a movable plate. This movable plate allows for adjustments to the folded waveguide length, consequently altering the phase of electromagnetic waves. The advantage of GGW technology is that it does not require electrical contact between different parts of a structure. Therefore, it enables the moving parts to slide freely without electromagnetic energy leakage, resulting in improved insertion loss in high-power applications. In addition, in the proposed design, the position of the input and output waveguide ports of the phase shifter remains fixed, which is advantageous from a practical point of view. As shown by measurement and simulation results, there is nearly 37% impedance bandwidth with the highest insertion loss of 0.6 dB, and the developed device has a maximum phase shift of 770° at the center frequency of 13 GHz. The phase shifter can be used for various radar and satellite applications that require phase control, such as beamforming networks and phased array antennas.

Magnonic combinatorial memory

In this work, we consider a type of magnetic memory where information is encoded into the mutual arrangement of magnets. The device is an active ring circuit comprising magnetic and electric parts connected in series. The electric part includes a broadband amplifier, phase shifters, and attenuators. The magnetic part is a mesh of magnonic waveguides with magnets placed on the waveguide junctions. There are amplitude and phase conditions for auto-oscillations to occur in the active ring circuit. The frequency(s) of the auto-oscillation and spin wave propagation path(s) in the magnetic part depends on the mutual arrangement of magnets in the mesh. The propagation path is detected with a set of power sensors. The correlation between circuit parameters and spin wave path is the basis of memory operation. The combination of input/output switches connecting electric and magnetic parts and electric phase shifters constitute the memory address. The output of the power sensors is the memory state. We present experimental data on the proof-of-the-concept experiments on the prototype with three magnets placed on top of a single-crystal yttrium iron garnet Y3Fe2(FeO4)3 (YIG) film. There are three selected places for the magnets to be placed. There is a variety of spin wave propagation paths for each configuration of magnets. The results demonstrate a robust operation with an On/Off ratio for path detection exceeding 35 dB at room temperature. The number of possible magnet arrangements scales factorially with the size of the magnetic part. The number of possible paths per one configuration scales factorial as well. It makes it possible to drastically increase the data storage density compared to conventional memory devices. Magnonic combinatorial memory with an array of 100 × 100 magnets can store all information generated by humankind. Physical limits and constraints are also discussed.

Design of a 0.15-2GHz high-resolution vector-sum broadband phase shifter with controlled programmable attenuators for stochastic cooling system.

In this paper, a new 0.15-2GHz broadband phase shifter with 9-bit phase resolution is presented. This broadband digital adjustable phase shifter is implemented by utilizing the signal vector summation technology. The phase shifter consists of one 90° hybrid coupler, two digital attenuators, two 180° hybrid couplers, two microwave switches, and one combiner. By adjusting the attenuation value of the two digital attenuators, the device creates a minimum 0.7° stepped phase shift. In addition, by switching the two microwave switches, a 360° range of phase shift is achieved while almost keeping the amplitude of the phase shifter constant. The measurement results show that the proposed phase shifter achieves a phase resolution of 0.7° while exhibiting an average insertion loss of 9 ± 2 dB and phase unbalance within ±10°. The calculated RMS phase error of the broadband phase shifter is below 5° from 0.15 to 2GHz.

Broadband phase shifter based on SiN-MoS2 integrated racetrack resonator.

As the critical device of microwave photonics and optical communication, the low-loss and high-efficiency optical phase shifter has attracted intense attention in photonic integrated circuits. However, most of their applications are restricted to a particular band. Little is known about the characteristics of broadband. In this paper, an SiN-MoS2 integrated broadband racetrack phase shifter is demonstrated. The coupling region and the structure of the racetrack resonator are elaborately designed to improve the coupling efficiency at each resonance wavelength. The ionic liquid is introduced to form a capacitor structure. Then, the effective index of the hybrid waveguide can be efficiently tuned by adjusting the bias voltage. We achieve a phase shifter with a tunable range covering all the WDM bands and even up to 1900 nm. The highest phase tuning efficiency is measured to be 72.75 pm/V at 1860 nm, and the corresponding half-wave-voltage-length product is calculated as 0.0608 V·cm.

A Tunable Dual-Circularly Polarized Antenna With Broadband Triple-Branched Feed Structure

A novel reconfigurable circularly polarized (CP) patch antenna with tunable operation band and switchable polarization states is proposed. Four varactors are placed symmetrically across the cross-shaped slot on the upper square patch so that the operation band of the proposed antenna can be continuously controlled through the specially designed bias. Meanwhile, a triple-branched broadband switchable feed structure loaded with p-i-n diodes is specially designed to achieve polarization reconfigurability (LHCP, RHCP). The structure novelly integrated a 180 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> broadband phase shifter with a 90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> one by a shared reference branch. Simulation results of the feed structure exhibit stable phase-shift in a wide bandwidth of 58.7 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\%$</tex-math></inline-formula> under <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm 5^{\circ }$</tex-math></inline-formula> phase imbalance. A prototype of the antenna is fabricated while both measured and simulated results agree well. The antenna achieves good impedance matching from 2 to 2.7 GHz and the axial ratios at both polarization states are smaller than 3 dB. The frequency and polarization reconfigurability make the antenna potentially suitable for satellite applications, such as multifrequency satellite data link transceiver.

STO/PDMS composite film achieving continuously tunable terahertz phase modulation via mechanical and thermal regulation

Phase is the basic property of electromagnetic waves, and controlling the phase is one of the eternal research topics in the field of electromagnetic waves. Here, a broadband terahertz phase shifter made of polydimethylsiloxane (PDMS) and strontium titanate (STO) has been theoretically proposed and experimentally demonstrated. The mixed material design gives the phase shifter the dual properties of PDMS and STO. Therefore, the phase shifter can not only change the thickness through stretching but also change the effective refractive index through temperature changes. The thickness and refractive index changes directly cause the transmission phase of the phase shifter to move synchronously. Because the material does not have frequency selection characteristics, the phase shifter realizes customized phase control in a wide range of the terahertz band. In the experiment, any phase shift can be achieved by adjusting the doping ratio, stretching ratio, and temperature. The proposed broadband phase shifter is simple to fabricate and has various control methods, which provides a variety of modes of terahertz wave phase modulation.

A Novel Wideband 90° Filtering Phase Shifter Using Broadside-Coupled MSLs

This brief presents a novel wideband 90° phase shifter using broadside-coupled microstrip lines (MSLs). Firstly, compared with its traditional counterpart, the proposed one can significantly increase the coupling degree as inquired in the traditional design so as to realize a much wide operating bandwidth in a simple topology. Secondly, for facilitating the design process, this brief introduces a synthesis method to efficiently design the proposed broadband phase shifter with prescribed parameters. Finally, to verify the proposed design, a prototype of the proposed phase shifter is designed, fabricated, and measured. The measured results show that the wideband phase shifter proposed in this brief can achieve 90°±3°, S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> <−22 dB, and fractional bandwidth (FBW) of 80%.

100 GHz micrometer-compact broadband monolithic ITO Mach–Zehnder interferometer modulator enabling 3500 times higher packing density

Abstract Electro-optic modulators provide a key function in optical transceivers and increasingly in photonic programmable application-specific integrated circuits (ASICs) for machine learning and signal processing. However, both foundry-ready silicon-based modulators and conventional material-based devices utilizing lithium-niobate fall short in simultaneously providing high chip packaging density and fast speed. Current-driven ITO-based modulators have the potential to achieve both enabled by efficient light–matter interactions. Here, we introduce micrometer-compact Mach–Zehnder interferometer (MZI)-based modulators capable of exceeding 100 GHz switching rates. Integrating ITO-thin films atop a photonic waveguide, one can achieve an efficient V π L ${V}_{\pi }L$ = 0.1 V mm, spectrally broadband, and compact MZI phase shifter. Remarkably, this allows integrating more than 3500 of these modulators within the same chip area as only one single silicon MZI modulator. The modulator design introduced here features a holistic photonic, electronic, and RF-based optimization and includes an asymmetric MZI tuning step to optimize the extinction ratio (ER)-to-insertion loss (IL) and dielectric thickness sweep to balance the trade-offs between ER and speed. Driven by CMOS compatible bias voltage levels, this device is the first to address next-generation modulator demands for processors of the machine intelligence revolution, in addition to the edge and cloud computing demands as well as optical transceivers alike.

A Compact Broadband Phase Shifter Based on HMSIW Evanescent Mode

A compact broadband phase shifter based on the half-mode substrate-integrated waveguide (HMSIW) is proposed in this letter. By etching interdigital capacitor or adding blind holes and patches into the HMSIW, the width of the HMSIW can be reduced. Moreover, based on the complementary phase responses of series capacitance and shunt capacitance loading on the HMSIW, a broadband phase shifter is designed with a small phase deviation. To validate the proposed design approach, two phase shift channels and the reference channel are fabricated and measured. Phase shifts of 86° ± 2.5° (and 43.5° ± 2.5°) with fractional bandwidths of 53.3% (and 35.7%) covering central frequencies of 7.5 GHz (and 8.4 GHz) are achieved. The insertion losses of the three channels are 0.76-1.32, 0.40-0.63, and 0.87-1.40 dB, respectively. Besides, the area of each branch is only 0.343λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ; λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> is the guided wavelength at the center frequency in the dielectric.

Beam-Switching antenna array with dual-circular-polarized operation for WiMAX applications

In this paper, a multi-layered dual circularly-polarized (CP) beam-switching antenna array is presented. The designed beam-tilting antenna array includes dual CP elements to support polarization diversity and pattern switching and two symmetrical novel combinations of the Butler matrix in two sides of radiating elements. The Butler matrix input ports on each side of the 1 × 4 arrangement of antenna elements control the polarization diversity. The Butler matrix consists of the broadband phase shifters and patch couplers. The proposed phase shifter is designed based on the aperture coupling technique for extending its 45-degree phase bandwidth. The single element of the antenna includes a reflector and two layers of substrate. The polarization of the proposed element is controlled with two microstrip lines at the end of a 90-degree patch coupler and a circular slot plays as the radiation section at another side of microstrip lines. The parasitic patch, helps to improve the impedance bandwidth and gain of the element. The proposed beam-switching antenna array supported WiMAX applications. The beam-forming network is fabricated and measured. The measured results of the fabricated antenna have a good agreement with simulated ones.

Reconfigurable terahertz rainbow deflector

Dynamic terahertz (THz) beam steering is a promising technique for numerous applications, including communication, high-resolution imaging, and radar. However, advances in this technology are considerably limited by inadequate broadband and active phase shifters at THz frequencies. In this paper, we developed a type of VO2-based device capable of broadband THz beam steering. The effect of the tunable Brewster angle of the VO2 thin film along with the insulator-to-metal transition process was verified. We demonstrated that the VO2 grating could realize a dispersive beam deflector in a broad frequency band. Furthermore, upon heating, the VO2 grating could switch between three states of mirror reflector, “rainbow” deflector, and metallic grating. We believe that the proposed reconfigurable and broadband THz beam deflector offers a powerful avenue for manipulating THz beams.

Simulation of the image rejection phase method

The paper considers the algorithmic possibility of the image rejection method. The main resulting characteristics of circuits implementing the above method are presented. The simulation model allows estimating the selectivity coefficient as a function of the phase and amplitude imbalance of the circuit branches. Mathematical and circuit simulations were conducted. The results of different modeling methods coincide, and the simulation results verify the possibility of implementing the image rejection method. On the basis of this model it is possible to provide a high level (at least 40 dB) of image rejection by amplitude and phase circuit imbalance compensation. The dependence of the noise level at the output of the image rejection circuit as a function of the circuit elements frequency characteristics is given. The results of this work could be used for further practical implementation of above mentioned method at the stage of selecting elements based on an analysis of their characteristics. The simulation model could be used to select required radioelements and to estimate image rejection level. It is possible to estimate the level of image channel suppression, the noise level and the signal-to-noise ratio at the output of the image rejection circuit by using the above mentioned mathematical models and characteristics of the selected elements for practical implementation of the circuit. The effect of the broadband phase shifters on the noise level is considered with the implementation of the above method as an example. It was shown that ensuring a high level of selectivity in order to minimize the noise level of the image channel is advisable only up to some values (about 25 dB). Further improvement of selectivity, for example, by minimizing the phase and amplitude balances, or mutual compensation of the mixer and phase shifter branch imbalances are necessary, if there are requirements for increasing the signal-to-noise ratio. It is shown that it is possible to ensure selectivity of up to 25 dB and a noise level reduction of 2.5-3 dB if the amplitude imbalance of the circuit is up to 1 dB, and the phase imbalance is up to 5 deg. in the required frequency band.

Optical Generation/Detection of Broadband Microwave Orbital Angular Momentum Modes

In this article, a novel electrically controlled optical broadband phase shifter (ECO-BPS) is proposed and experimentally investigated for broadband microwave orbital angular momentum (OAM) mode generation. Based on the proposed ECO-BPS and a 17-element circular antenna array, the effect of the phase error on the OAM mode quality is studied by comparing the OAM modes respectively synthesized by three phase schemes: ideal phase shifts, ECO-BPS phase shifts, and optical true time delay phase shifts. In addition, the crosstalk caused by the phase error in applications of OAM modes multiplexing is investigated in a Dammann vortex grating based OAM modes demultiplexing system. All numerical simulation results demonstrate the feasibility of the ECO-BPS in broadband microwave OAM applications.

Brillouin-based phase shifter in a silicon waveguide

Integrated silicon microwave photonics offers great potential in microwave phase shifter elements, and promises compact and scalable multi-element chips that are free from electromagnetic interference. Stimulated Brillouin scattering, which was recently demonstrated in silicon, is a particularly powerful approach to induce a phase shift due to its inherent flexibility, offering an optically controllable and selective phase shift. However, to date, only moderate amounts of Brillouin gain has been achieved and theoretically this would restrict the phase shift to a few tens of degrees, significantly less than the required 360 degrees. Here, we overcome this limitation with a phase enhancement method using RF interference, showing a 360 degrees broadband phase shifter based on Brillouin scattering in a suspended silicon waveguide. We achieve a full 360 degrees phase-shift over a bandwidth of 15 GHz using a phase enhancement factor of 25, thereby enabling practical broadband Brillouin phase shifter for beam forming and other applications.

Fabrication and characterization of microwave phase shifter in microstrip geometry with Fe film as the frequency tuning element

Abstract A series of ultra-small planar broad-band phase shifters with wide range of phase shift are designed and tested in this investigation. To achieve this performance a series of microstrip transmission lines with Iron (Fe) films of various thicknesses (from 100 to 800 nm) were designed, fabricated and tested. The basic principle of operation of these phase shifters are based on ferromagnetic resonance (FMR). The influence of the thickness of the magnetic layer was studied for two frequency regions: below and above the ferromagnetic resonance. This is because for a real-device the insertion loss should be less than −3 dB (or as low as possible). In the high frequency region, the optimal frequency (corresponding to the highest change in phase shift) increased significantly with the increase of the Fe film thickness (from 27 GHz for the structure with 100 nm of Fe to 43 GHz for the structure with 800 nm of Fe film). In the low frequency region, however, the optimal frequency varied little with the Fe layer thickness. The highest change in phase shift (~90 deg/cm) corresponded to the structure with the thinnest Fe layer for the low frequency region and with the thickest Fe layer for the high frequency region. In the high frequency region the Figure-of-Merit was about 20 deg/dB at low magnetic fields (

Wide-Band Filtering Three-Port Coupler With Inherent DC-Blocking Function

This paper presents a novel wide-band filtering three-port coupler with inherent DC-blocking function, which is simply comprised of a power divider with wideband filtering function and a broadband phase shifter with a modified coupled line. For demonstration, a designed prototype operating at 3 GHz is simulated, fabricated, and measured. From the simulated and measured results, the coupler shows a 49% filtering bandwidth with 12-dB return loss and 90° ± 590°phase shifting. The amplitude imbalance between the two output ports is less than 0.5 dB. The all-passband isolation is below −13 dB and the 25.7-dB upper stopband rejection is up to 5.4 GHz. Good agreement between the simulated and measured results validates the proposed idea. Hence, the proposed coupler is well suited for the applications of wideband, filtering, and single-layer circuitry integration.

Single-Layer Broadband Phase Shifter Using Multimode Resonator and Shunt $\lambda $ /4 Stubs

This paper presents a new method for single-layer broadband phase shifter without needing any coupling structure. The phase shifter consists of a multimode resonator and two shunt $\lambda $ /4 stubs. Meanwhile, the bandwidth of proposed phase shifters can be achieved more than 100%. For prescribed return loss, phase shift value, and phase error, this paper develops a synthesis approach to determine all parameters of designed phase shifter. In addition, both the return-loss bandwidth and phase-error bandwidths can be considered simultaneously so as to determine the return loss and phase error for a desired bandwidth. The 45°, 90°, 135°, and 180° phase shifter are theoretically designed and presented. To validate the design method, a broadband 90° phase shifter is designed, fabricated, and measured. The synthesized, simulated, and measured results are found in good agreement with each other, and the experimental results show that the phase shifter achieves 90° ± 5°, $\vert S_{11}\vert dB, and insertion loss < 0.7 dB over the bandwidth from 1.43 to 4.45 GHz (102.7%).

基于复合左右手传输线的移相器设计

本文利用复合左右手传输线特殊的非线性相位响应特性，提出一种宽带移相器的设计方法。宽带移相器的使用可以控制天线波束在宽带内实现较固定的倾角。该方法由主副两个通路组成四端口的差分移相，其中主通路由复合左右手传输线组成，副通路由传统的右手传输线构成。两通路在很宽的带宽内相位变化一致，能够实现宽带移相。通过HFSS软件仿真设计出90˚移相器，在8~15.9 GHz (66.4%)带宽内相位不平衡度为±3˚，带内回波损耗 < −12 dB，最大插入损耗为0.3 dB。该结构设计简单，加工方便。 A design of broadband phase-shifter is presented by utilizing the unique nonlinear phase response of the composite right-left handed transmission line. The use of wideband phase-shifter can control antenna beam to achieve a fixed angle in broadband. The four-port differential phase- shifter consists of two paths, one path using composite right-left handed transmission line while the other using conventional right hand transmission line. A stable phase difference can be obtained over a wide bandwidth, so that broadband phase shift can be achieved. Simulated results show that the 90˚, phase-shift with phase imbalance of ±3 can be achieved over a broad bandwidth from 8 GHz to15.9 GHz (66.4%), with the return losses more than 12 dB and the insertion losses less than 0.3 dB. Moreover, the proposed structure is easy to design and convenient to fabricate.