Transmission Line Phase Shifter Research Articles

A Singly Curved Conformal Phased Array with Integrated Particles-Based CRLH Phase Shifters

In this paper, a four unit cell micron-sized magnetic particles embedded composite right/left-handed (CRLH) transmission line metamaterial phase shifter is proposed. The variable phases are achieved by activating the micron-sized magnetic particles along the length of stub transmission lines of the CRLH transmission line structure. This causes to effectively change the inductance of stub transmission lines, which changes the phase of the RF signal. These structures can be activated in a symmetric or asymmetrical manner to obtain wide range of phase shifts. A prototype of cascaded four unit cell CRLH transmission line phase shifter with embedded silver-coated ferrites (magnetic particles) is designed, fabricated and tested for phase shifters applications. The measured phase response of the proposed phase shifter is in close agreement with the simulated phase response. Next, for the performance analysis of proposed phase shifter, a 1 × 4 conformal curved-shaped phased array operating at 5.8 GHz is fed with the four unit cell cascaded phase shifter in CST full-wave simulator. The conformal phased array with proposed integrated phase shifters was simulated for broadside pattern correction and main beam scanning at 20 degree on curved-shaped surface with different bend angles. The radiation pattern results obtained with the proposed integrated phase shifters are in close agreement with those obtained with direct excitation of the array.

A reconfigurable Wilkinson power divider based on transmission-line phase shifter for 5G new radio

A reconfigurable Wilkinson power divider based on transmission-line phase shifter for 5G new radio

A W-Band Digitally Controlled Bidirectional Transmission Line Phase Shifter in 22-nm FDSOI

In this letter, a passive bidirectional integrated tunable transmission line (TL) phase shifter (PS) is proposed and demonstrated in the W-band (75–110 GHz). The PS is based on a modified coplanar waveguide (CPW) structure with a conditional meandering ground return path located below the coplanar metal layer on the ground wall. The modified CPW structure achieves a wide phase shift tuning range with a compact PS unit cell A 5-bit digitally controllable PS based on the proposed topology is implemented in the 22-nm fully depleted silicon-on-insulator (FDSOI) process. The PS achieves a worst case phase resolution and loss of 4.4 <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> and 11.5 Db, respectively, in the W-band for a total phase shift of up to 115 <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> . To the authors’ knowledge, this represents the highest frequency range for a constant length integrated tunable TL PS in a silicon-based integrated circuit (IC) technology.

Single-Input Broadband Hybrid Doherty Power Amplifiers Design Relying on a Phase Sliding-Mode of the Load Modulation Scheme

This work introduces a novel design theory for a single-input hybrid Doherty power amplifier (PA) inspired by the design space existing within the previously reported dual-input Doherty–Chireix (outphasing) continuum. Unlike the conventional <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda /4$ </tex-math></inline-formula> Doherty PA inverter which only performs the correct load modulation at its center frequency, the hybrid Doherty PA (HD <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\omega $ </tex-math></inline-formula> -PA) combiner network achieves a wideband load modulation using the frequency dependence of the electrical length of the output combiner lines versus frequency for sliding the PA mode of operation. A modified theory is presented in this work to allow for a single-input PA implementation. In this new design, the outphasing angle is only changing with frequency and not the input power. A transmission line phase shifter is used to provide the correct frequency-dependent input phase offset ensuring the correct wideband load modulation performed by the output combiner. A novel methodology is also proposed to select the optimal input phase offset to reduce the variation in the saturation power versus frequency and minimize the circuit size. A proof-of-concept demonstrator PA circuit is designed to operate from 2.5 to 3.3 GHz. When the fabricated PA is excited by a 20-MHz long-term evolution (LTE) modulated signal with 6-dB peak-to-average-power ratio (PAPR), an average efficiency of 45%–59% and adjacent channel leakage ratio (ACLR) less than −50 dBc are achieved after digital predistortion (DPD) across the entire band. When the fabricated PA is excited by a 5G-like 50-MHz orthogonal frequency-division multiplexing (OFDM) signal with 10-dB PAPR, an average efficiency of 33%–41% and ACLR less than −44 dBc are achieved after DPD across the entire band.

A 16.5-31 GHz Area-Efficient Tapered Tunable Transmission Line Phase Shifter

This paper presents a Tapered Tunable Transmission Line (Tapered TTL) phase shifter that achieves a higher area efficiency than conventional Tunable Transmission Line (TTL) phase shifters while maintaining the same phase shift range with similar insertion losses. A systematic methodology is provided for the optimum design of the proposed phase shifter to maximize its area efficiency while providing the desired phase shift range and satisfying the maximum allowed input/output return and insertion losses. To verify the efficacy of the proposed solution, an eleven-cell phase shifter is fabricated in a standard 65-nm Complementary Metal–Oxide–Semiconductor (CMOS) technology and the measurement results are reported. The fabricated circuit provides a 180-degree phase shift over the frequency range of 16.5 to 31 GHz with an average insertion loss of 7.2 dB. The proposed design presents a 25 percent reduction in the chip area per unit delay in comparison to the conventional design with the same average insertion loss.

Design and Minimization of Mutual Coupling Steered Array Lens Antenna for 5G Communication

Examining and evaluating the improved microstrip patch antenna to enhance the performance by the initial objectives are the main contribution of this paper. To achieve multiband operation, the patch's shape is first adjusted later microstrip patch with the slot presented. With the help of the Ansoft HFSS antenna simulator, functional analysis has been shown to examine the impact on antenna resonant frequency. A probe-driven microstrip patch antenna imprinted on FR4 epoxy substrate with 1.6mm thickness and a dielectric constant of 4.4 is developed in this work via the HFSS tool for wireless applications operating between 2 to 5GHz. To achieve multiband operation, the structure of the patch is varied. The impacts on antenna resonant frequency are examined through numerical simulations. The length, as well as the width of a traditional patch antenna, is initially computed, and further, an appropriate patch dimension of 28.3mm x 36.9mm has been determined. For multiband operation over the frequency ranging between 2 and 5GHz wireless applications, a probe-driven microstrip patch antenna imprinted on FR4 epoxy substrate with 1.6mm thickness and a dielectric constant of 4.4 is built via the HFSS tool. The proposed architecture of a traditional microstrip patch antenna is imprinted on an FR4 epoxy substrate with a 1.6mm thickness and a 4.4 dielectric constant. The proposed antenna design is illustrated for the 3D structure of the Mutual Coupling Steered Array-Lens Antenna System (MPA) with an improved patch. To achieve multiband operation, two slots are inserted on the edges of the patch, and both the slots are 2mm wide, as well as the depth of the slots is modified to see how it corresponds to the resonant frequency. This work is mainly concentrated on (i) Examining as well as evaluating the improved microstrip patch antenna to enhance its performance, (ii) Examining, evaluating, as well as assessing the performance of an improved split ring resonator metamaterial, and (iii) Exploring, analyzing, as well as evaluating the performance of dielectric lens base patch array antennas and (iv) Developing as well as analyzing the transmission line phase shifter. The groundwork for developing this work is being carried out, and a comparative study is made on (i) techniques for improving the antenna's performance through the application of a modified patch antenna, a Modified split ring resonator, a Dielectric lens structure, and Transmission line phase shifter.

Ka‐band distributed microelectromechanical systems transmission line phase shifter using metal air metal switch

AbstractA new approach for designing a two‐state unit cell for a six‐bit distributed coplanar waveguide microelectromechanical systems (MEMS) phase shifter is proposed in this study. The proposed structure includes metal air metal (MAM) capacitors as switches and consists of a unit cell with one MEMS and two MAM switches to produce two phase shifts per unit cell. In the first state, the MAM switches are pulled down and a 5.625° phase shift is achieved, and in the second state, the MEMS switch is actuated to yield a phase shift of 11.25°. The designed structure is modeled using equivalent transmission line circuit model and simulated in the Ka‐band at 34 GHz, employing advanced design system (ADS), ANSOFT HFSS and COMSOL software. Based on the modeling and simulation results, the root‐mean‐square (RMS) phase error is 1.4°, and maximum return loss and minimum insertion loss for all 64 states are better than −10.1 and −1.45 dB, respectively. The main advantages of the designed structure are its small size, low loss, low phase error and a simple phase shift mechanism. A fabrication process is also proposed for the distributed MEMS transmission line (DMTL) phase shifter that shows the feasibility of the proposed design. The proposed structure can be easily scaled to other bands and used in applications with more bits as complex as phased array antennas.

Three-Bit DMTL Phase Shifter for Phased Array Antennas

RF MEMS phase shifter is a device that is used to modify the transmission phase of RF signal and provide signal control. Phase shifters are high-value components used in phased array antenna architectures. In phased array antenna the phase shifter is used to provide reliable electronic beam steering. The proposed 3-bit distributed MEMS transmission line (DMTL) phase shifter is designed using elevated coplanar waveguide (ECPW) transmission line for the first time, which results in better return loss of [Formula: see text]14.23[Formula: see text]dB and an average insertion loss of [Formula: see text]1.46[Formula: see text]dB. This paper discusses the development of ECPW-based 3-bit DMTL phase shifter designed to operate at 15[Formula: see text]GHz.

A 60-GHz Transmission Line Phase Shifter Using Varactors and Tunable Inductors in 65-nm CMOS Technology

This paper describes a 60-GHz artificial transmission line phase shifter designed in 65-nm CMOS technology. To increase the phase shift range and preserve the matching over the entire phase shift range, the fixed series inductors in the standard line cell are substituted by tunable inductors. The required tunable inductors are constructed using a transformer with the transformer secondary loaded by a varactor. To verify the operation principle, the phase shifters, including one-, two- and three-cell, are manufactured. The experimental phase shift range is 45° for one-cell, 92° for two-cell, and 133° for three-cell line shifters. These figures are nearly 80% larger than the corresponding phase shifts in the lines consisting of cells with fixed inductors. The input/output return loss is less than 10 dB for all cases over the entire phase shift range. The average insertion loss is 3.2 dB for one-cell, 5.6 dB for two-cell, and 7.8 dB for three-cell transmission line phase shifters. The proposed continuous phase shifter achieves the highest phase shift range per area among the millimeter-wave transmission line and switch-type phase shifters reported to date.

A New Structure for 6 Bit Distributed MEMS Transmission Line Phase Shifter in Ku Band

In this paper a new design for 6 bit DMTL phase shifter with only 32 MEMS switches is proposed. The reduction in number of switches in ordinary 6 bit phase shifter from 63 to 32 is due to combination of one 5.625 degree for least significant bit and 11.25 degree for the rest of the switches. Decreasing the number of the switches reduces the die-size as well as loss of the CPW line. Analytical study and simulation with HFSS and COMSOL software is carried out for the proposed structure. Maximum return loss of phase shifter is -10.5 dB and mean RMS phase error is 1.4o . Although two different structural switches are used but the pull in voltages are identical. The total structure size is 1.5*18.5 mm2 , and surface micromachining process is proposed for the phase shifter.

Fully Printed Static Gain Reconfigurable Conformal Patch Antenna Arrays

Abstract This work presents design and fabrication processes for creating statically gain-reconfigurable conformal patch array antennas. In our previous work, a fully printable and conformal antenna array on a flexible substrate with a new Left-Handed Transmission Line (LHTL) phase shifter based on a Barium Strontium Titanate (BST)/polymer composite was computationally studied for radiation pattern correction and beam steering applications. In this work, additive manufacturing techniques were used to experimentally demonstrate the phase compensation needed to improve the degraded performance of the conformal arrays. An Aerosol Jet direct-write printer was used to print several patch antenna arrays and was tested in an anechoic chamber to establish baseline gain metrics. Once a baseline is established, a high dielectric constant material (BST nano-ink) was dispensed onto the IDCs in several configurations, to provide the necessary phase compensation. The antennas were retested and the changes in their gain profiles were investigated. The findings of this work and the proposed method allow for gain compensation of curved conformal antennas and post-production modification of the radiation pattern of antenna arrays. This work has potential applications in the automotive industry due to the low cost of production and the ability to be integrated onto curved conformal surfaces without interfering with super structure or other mechanical design related criteria.

Design of a UHF wide‐band antenna with a compact notch filter

A novel ultra high frequency (UHF) broadband polygonal monopole antenna with a notch is presented. The antenna is a wineglass-shaped geometry near two pairs of long-horn-shaped coupling elements located on the top and bottom surfaces to cover the band of 700 MHz–1.3 GHz with the size of 150 × 100 × 1.2 mm. The notch filtering is achieved at 900 MHz by using the open-terminated stub of a novel composite right/left handed transmission-line phase shifter. The phase shifter is 12 mm as 0.07 × λg. The validity of the proposed scheme is verified by designing and comparing the wide-band antenna with different notch-making approaches through electromagnetic simulation, fabrication and measurement. The simulated and measured results show high degrees of agreement. The suggested antenna is shown to be useful for UHF-band applications with a stopband at 900 MHz to avoid potential interference from the GSM-E service, Z-wave communication and UHF radio-frequency identification tag frequencies.

DESIGN AND SIMULATION OF FULLY PRINTABLE CONFORMAL ANTENNAS WITH BST/POLYMER COMPOSITE BASED PHASE SHIFTERS

A fully printable and conformal antenna array on a flexible substrate with a new Left- Handed Transmission Line (LHTL) phase shifter based on a tunable Barium Strontium Titanate (BST)/polymer composite is proposed and computationally studied for radiation pattern correction and beam steering applications. First, the subject 1 × 4 rectangular patch antenna array is configured as a curved conformal antenna, with both convex and concave bending profiles, and the effects of bending on the performance are analyzed. The maximum gain of the simulated array is reduced from the flat case level by 34.4% and 34.5% for convex and concave bending, respectively. A phase compensation technique utilizing the LHTL phase shifters with a coplanar design is used to improve the degraded radiation patterns of the conformal antennas. Simulations indicate that the gain of the bent antenna array can be improved by 63.8% and 68% for convex and concave bending, respectively. For the beam steering application, the proposed phase shifters with a microstrip design are used to steer the radiation beam of the antenna array, in planar configuration, to both negative and positive scan angles, thus realizing a phased array antenna.

Modeling of LTCC-Ferrite Tunable Inductors and Development of an &lt;inline-formula&gt; &lt;tex-math notation="LaTeX"&gt;$\boldsymbol {L}$ &lt;/tex-math&gt;&lt;/inline-formula&gt;-Band Phase Shifter

This paper presents the modeling of a tunable inductor using a low-temperature co-fired ceramic (LTCC)-ferrite tape and subsequent development of a loaded transmission line phase shifter using these inductors. The inductors are initially realized in the form of circular disks fabricated from commercially available ferrite tape (ESL 40011) wound with a copper wire. A complete model of this inductor is obtained between 0.3 and 4 GHz and validated by measurements. The phase shifter comprises these inductors in shunt, thus minimizing the effect of low-field magnetic losses in $L$ -band. The magnetic material is operated below the resonance region in a partially magnetized state with the help of a bias current that configures the phase shifter electronically. The phase shifter exhibits an insertion loss of 2 ± 0.5 dB and a differential phase shift varying between 35° and 10° in the above band. Finally, to demonstrate the feasibility of integration with other RF components, a working prototype of the same phase shifter that is fully integrated in LTCC is also presented with measurements.

The MTT-S Historical Collection [MTT World

The at the 2014 International Microwave Symposium (IMS2014) in Tampa, Florida, USA, marked the 35th anniversary of the IEEE Microwave Theory and Techniques Society (MTT-S) Historical Collection. The collection was started and first displayed at IMS1980 in Washington, D.C. According to a report by Ted Saad: At the 15 January 1980 MTT-S Administrative Committee (AdCom) meeting in Washington, D.C., Dr. Steve Adam, the then AdCom president, gave me the task of preparing a historical exhibit for the 1980 MTT-S Symposium to be held in Washington on 28–30 May 1980. No specifications or instructions were given. The was an outgrowth of a suggestion on the part of Dr. John Horton, who for several years had proposed some type of microwave hall of fame. The collection has grown steadily over the years and now consists of more than 1000 cataloged items. At the end of 2014, there were 522 pieces of hardware, 328 books, 196 miscellaneous documents, and 14 videos. The hardware artifacts comprise; 353 tubes, including gridded types, klystrons, magnetrons and other crossed-field types, radar transmit‐ receive (T/R) tubes, and tube components; 76 subassemblies or modules, including amplifiers, oscillators, and various test equipment; 56 transmission line items, including couplers, slotted lines, variable attenuators, phase shifters, and filters; 37 individual solid-state components. Some of the artifacts are one-of-akind experimental pieces like the copper- foil-lined wooden block that was used as a waveguide coupler. Many are samples of mass quantities taken from the production line. The oldest truly microwave items are two 1932 splitanode magnetrons from Ross Kilgore of Westinghouse. The newest is a 1996 Litton mini traveling-wave tube (TWT). The books include engineering texts such as a complete 28-volume set of the MIT Radiation Laboratory (Rad Lab) series, biographies of various individuals, company histories, and manufacturers' catalogs.

Microfabricated Thick-Cu PZT-MEMS Millimeter-Wave Topologies and Devices

This letter reports the design, fabrication, and performance of millimeter-wave transmission lines and devices in a tri-layer thick-copper (Cu) process. Beneath the Cu layers is a low-voltage lead zirconium titanate (PZT) MEMS stackup atop a nitride membrane, on high-resistivity silicon. The 10 μm thick Cu layers enable several transmission-line topologies, and the PZT-MEMS functionality enables tunability. We designed transmission lines and un-optimized noncontact distributed MEMS transmission line (DMTL) phase shifters for 75-110 GHz, and present static measurements here. Simulation and measurements are in close agreement, with measured CPW line loss 0.15 dB greater than simulated (0.27 dB/mm at 95 GHz). Excess loss is attributed to Cu roughness, conductivity, and membrane/strap supports. Measured noncontact DMTL phase shifters exhibit a mean of 40 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> /dB when intrinsic line loss is subtracted.

A CMOS Voltage Controlled Continuous Phase Shifter With Active Loss Compensation

A voltage controlled RF linear phase shifter (VPS) on CMOS process is proposed and developed to address insertion loss variation over a control range, linearity of phase control, and the size of implementation. A new compensation method for a transmission line phase shifter is introduced. By compensating loss associated with lumped elements in a transmission line, the measured CMOS VPS achieves minimum 2.8 dB insertion loss and ±0.6 dB insertion loss variation over 120° phase shift at 1.95 GHz, consuming 4 mA from 1.8 V supply. The size of the phase shifter is 850 μm × 440 μm without pads. The measured input P1dB of the design is higher than 4 dBm. To the best of author's knowledge, the demonstrated phase shifter achieves one of the best performances published in a CMOS process without using active inductors.

A LOW-COST PHASED ARRAY ANTENNA INTEGRATED WITH PHASE SHIFTERS COFABRICATED ON THE LAMINATE

This paper presents the design, development and experimental characterization of a monolithic phased array antenna integrated on a microwave laminate. A four-element linear antenna array is realized by cofabricating the corporate feed network, microstrip-CPW transitions, DC blocks, and mesoscale phase shifters on the same substrate. The phase shifters used here are electrostatically actuated and their operation is similar to that of the distributed MEMS transmission line phase shifters. Various components of the array are designed and are individually evaluated before fabricating together. The measured radiation pattern characteristics for this array shows a scan angle of 10 - in the X- band. All fabrication processes employed here can be performed at a good printed circuit manufacturing facility. This simple approach of cofabricating various components can be readily extended for large phased arrays required in radar and space communication applications.

Distributed transmission line phase shifter using parallel-plate ferroelectric thin film varactors

A distributed transmission line phase shifter based on two series connected parallel-plate ferroelectric thin film varactors, which are integrated into single crystal (1 0 0) LaAlO 3 (LAO) wafer, is presented. The equivalent circuit model was simulated by the EM simulation software in an effort to optimize the design. A device with differential phase shifts of 150 o at 8 GHz with a low bias voltage of 12 V was realized.

RFID Coverage Extension Using Microstrip-Patch Antenna Array [Wireless Corner

In this paper, a UHF-band 2 times 2 microstrip phased-array antenna is designed and implemented to extend the coverage of an RFID reader system. The phased-array antenna has four microstrip-patch antennas, three Wilkinson power dividers, and a transmission-line phase shifter. These are printed on a dielectric substrate with a dielectric constant of 4.5. The array has dimensions of 34 cm times 45 cm, operating at a frequency of 867 MHz, as specified in RFID Gen2 protocol European standards. The phased-array antenna has a measured directivity of 12.1 dB, and the main-beam direction can be steered to angles of plusmn 40deg, with a HPBW of 90deg. The phased-array antenna is used as the receiving antenna in a commercial reader system. Experimental results indicate that the coverage of the RFID system with the phased-array antenna is superior to the coverage with a conventional broader-beamwidth microstrip-patch antenna. The proposed system can also be used for a wireless positioning system.