Broadband Matching Research Articles

An enhanced efficiency 170–260 GHz frequency doubler based on three points resonance matching technique

This paper presents a full-band frequency doubler (170–260 GHz) with enhanced efficiency based on Schottky diodes. To achieve broadband matching between the matching circuit and the Schottky diode, a three points resonance matching technique (TPRMT) is employed. This technique is developed by considering the embedded impedance matching at three distinct frequency points: upper, middle, and lower, thereby guiding the design of the peripheral matching circuits. In comparison to single frequency point matching, this approach effectively suppresses sideband performance degradation, resulting in improved efficiency. Additionally, the peripheral matching circuits are meticulously designed to fulfill a resonance clockwise impedance trajectory, facilitating matching at the aforementioned three frequency points. Due to the limitation of the input power source, measurements were conducted only within the 170–237 GHz frequency band. The measured results show that the doubler achieves an efficiency ranging from 8.4 % to 14.1 % under an input power of 130–175 mW. The good consistency between simulation and measurement validates the significant advantages of TPRMT.

Study of the characteristics of broadband matching antennas for fifth-generation mobile communications based on new composite materials

The presented research aims to analyze in detail the characteristics of broadband matching antennas specifically designed for 5G mobile communications applications, with an emphasis on innovative composite materials. The study focuses on a compact planar loop antenna designed for use on smartphones, covering the LTE/WWAN frequency bands 824 to 960 MHz, 1,710 to 2,690 MHz, and 3,300 to 3,600 MHz for full coverage of modern 5G networks. Experimental and numerical methods are used to broadly analyze the frequency range associated with 5G networks. The features of the use of composite materials in the implementation of antenna devices in 5G technologies are noted. A broadband matching circuit (BMC) with elements with lumped parameters and a reduced sensitivity invariant has been synthesized. A 3D model of the adaptive selective surface controller (SSC) was developed using CST Studio. The study results highlight the benefits of new composite materials in improving the performance of 5G antennas. This research makes a significant contribution to the development of 5G technologies by optimizing antenna design for efficient data transmission in modern mobile networks and can be a valuable resource for engineers and designers working in this field.

A concise high‐efficiency broadband parallel‐circuit Class‐E power amplifier

SummaryAn analysis of a single‐ended high‐efficiency broadband parallel‐circuit (PC) Class‐E power amplifier (PA) with a single reactance compensation technique (RCT) and low‐pass (LP) Chebyshev impedance transformer is first presented under low supply voltage. Analysis of the gate and drain voltage allows to determine the required optimum voltage values for the expected PA design objectives. Derivation and design procedure of the broadband matching network (MN) is provided, which can effectively filter out higher order harmonics and reduce circuit complexity. In addition, the load adaptability for this PA is studied, achieving higher than 67.87% drain efficiency (DE) in the case of load mismatch. A PC Class‐E PA based on NMOS transistor is designed and implemented to validate the analysis over a frequency band of 7–9.4 MHz. Experimental results show that the PA delivers 36.48–38.83 dBm output power with a DE of 84.91% to 86.91%, as well as achieves 83.98% to 86.28% power‐added efficiency (PAE), 19.48–21.83 dB gain with a low supply voltage of 12 V. It is also demonstrated that the experimental results exhibit good agreement with the simulation results, which prototype the radio frequency identification transmitter with broadband high‐efficiency and system compactness. To the author's knowledge, this study represents the first approach to design broadband PC Class‐E PA under low supply voltage for Internet of Things (IoT) applications at HF frequency band, such as electronic article surveillance (EAS) system.

A Ka-Band Frequency Doubler With a Broadband Matching Scheme for Efficiency Optimization

A Ka-Band Frequency Doubler With a Broadband Matching Scheme for Efficiency Optimization

Area Efficient and Linear MMIC Based Ka Band Power Amplifier for 5G Communication Systems

This work presents a monolithic microwave integrated circuit (MMIC) based power amplifier (PA) with single 150 nm GaN high electron mobility transistor (HEMT) using broadband matching. For the proposed amplifier, two stage L-type biasing network is designed. In order to provide good linearity, low Q, broader bandwidth and optimized chip area, band pass filter (BPF) type matching network is proposed. The topology and parameter selection is done by performing proper load pull analysis. This helps in achieving wide band matching to maintain low Q factor. Thus the proposed amplifier is evaluated with post layout EM simulation data. For the 26 GHz band of 5G communication, proposed amplifier has a small signal gain of 11 dB for 21-27.4 GHz. The amplifier offers 33.42 dBm saturated output power and good linearity. The designed PA provides 31.35 dBm output power, 26% power added efficiency (PAE) and 29% drain efficiency (DE) at 1 dB compression with IP3 of 39.67 dBm for 26 GHz band. The designed PA has less complexity and small chip area of 4.3 mm2.

A 8–12 GHz power amplifier with high out-of-band rejection

This paper proposes an 8–12 GHz monolithic power amplifier (PA) with high out-of-band rejection. This PA adopts an impedance conversion technique to reduce the Q of the output impedance of the amplifiers for all stages, which is used to achieve broadband matching performance. In addition, the bandpass matching structures and a trap circuit are adopted to effectively suppress out-of-band signals. The proposed PA is fabricated by using a 0.5 μm GaAs pHEMT process. The measurement results show that the PA has an in-band small signal gain of 23 dB ± 0.7 dB, input and output return loss are both better than −14dB, the saturation output power is about 23dBm, the power-added efficiency (PAE) is better than 20 %, and rejection ratios are 65dBc and 51dBc at 3 GHz and 17 GHz respectively. The area is of 2.3mm × 1.1 mm.

A 6 to 18 GHz flat high gain power amplifier using mismatch-consistent MCR technique in 40-nm CMOS

This paper presents a power amplifier (PA) based on the mismatch-consistent magnetically coupled resonator (MCR) technique, which employs adjustable dual-pole to achieve a wide operating frequency range. The in-band no gain ripple condition of the proposed mismatch-consistent MCR is systematically analyzed and derived. By applying this condition to the mismatch-consistent MCR technique, the in-band gain flatness in broadband is improved. An ultra-wide wiring method for the power-combining structure is proposed to further improve the in-band gain flatness by reducing parasitic effects. Meanwhile, an active broadband matching network without any on-chip inductor is used to obtain a -11 dB input return loss (S11) across the whole bandwidth. Implemented in 40-nm CMOS process, the proposed PA achieves a saturated output power of 19.2 dBm, an output 1 dB compression point of 17.8 dBm, a peak power added efficiency of 29.7 %, and only 0.5 dB in-band gain ripple at 8.2-16.2 GHz. The amplifier achieves a 3 dB bandwidth from 6 to 18 GHz while the fractional bandwidth reaches 100 %, realizing wideband and flat frequency response.

Flexible Approximation Functions: Resonant Loads

Introduction. Patch antennas have found wide application in UAVs due to their numerous useful properties. However, since such an antenna system is essentially a resonator, the problem of its matching remains unresolved. The existing publications mostly deal with specific cases and report the typical values of the matching band of 5–7 %, which cannot be considered sufficient when there is a need to use the signal spectrum of up to hundreds of MHz. Therefore, research aimed at using more efficient methods of broadband matching could be of interest for engineers. Aim. To develop a broadband matching technique based on the generalized Darlington synthesis method using flexible approximating functions (AF) for load models with resonant properties. Materials and methods. The capabilities of the generalized Darlington synthesis method are extended AFs with increased variation properties. Flexible control of AF weight coefficients makes it possible to realize both smooth and wave frequency characteristics. The method is analytical and does not use iterative procedures. The mathematical apparatus of the method is based on an analysis of deductions in the zeros of the load resistance transfer function. Results. Flexible approximating functions were established to be effective for synthesis of matching circuits with resonant properties. Solutions for matching the loads with multiple transfer zeros both at the origin and in infinity were obtained. The opportunity of creating patch antennas with a matching layer up to 40 % and more was demonstrated. Conclusion. The results obtained for the SWR of patch antennas show that the potential estimates of matching limits are available only for analytical methods.

A New Technique for Broadband Matching of Open-Ended Rectangular Waveguide Radiator.

The maximum reflection at an open end of a standard rectangular waveguide is about -10 dB in its operating frequency range. It is often used without matching. For critical applications, it is desirable to further reduce the reflection coefficient. In this paper, a new technique is presented for the broadband impedance matching of an open-ended rectangular waveguide. The proposed technique employs three thin capacitive matching elements placed at proper intervals via a low-loss dielectric material. The capacitance of, and distance between, the matching elements are optimized for broadband impedance matching using a simulation tool. Based on the proposed technique, two design examples are presented for the matching of a WR75 waveguide radiator. A reflection coefficient of less than -16 dB and -20 dB has been achieved over a ratio bandwidth of 2.13:1 and 1.62:1, respectively.

Ultra-Wideband Six-Port Network Miniaturization—Matching

AbstractIn this paper, a new design approach for the six-port (SP) junction is introduced. The proposed design includes a generalized broadband matching and smooth miniaturization scheme and is extendable for any passive multiport structure. A multilayer technology and a microstrip to slot coupling operation are employed for the designed SP, which comprises power divider and three hybrid couplers. The conducted measurements of the constructed SP junctions validates the design approach. Optimal performance of the SP network in terms of miniaturization, bandwidth, and response accuracy were obtained for the 5G low band.

Design of a 0.8-2.2GHz ultra-wideband RF high power amplifier

Based on the self-developed standard process RF-LDMOS device, a new ultra-wideband RF power amplifier is designed in this letter. The amplifier removes the absorbing resistor and capacitor series structure at the end of the drain. The stability of the circuit is enhanced by the pre-matching circuit. Considering the small impedance value of the RF high-power device, it is difficult to achieve broadband matching. The novel tapering drain transmission has been developed which overcomes the distributed amplifier’s limitations of low power and efficiency. Ultra-wideband RF amplifier has excellent output power and efficiency. The measurement results show that from 0.8-2.2GHz, under the condition of 28V power supply, the saturated output power is 43dBm (20W), the power gain is 10dB, the drain efficiency is about 30%-50%; The peak-to-average ratio is 8dB, and the ACPR is less than -41dBc when the linear output is 5W, proving the effectiveness of the new tapered drain structure to achieve broadband.

Design of Broadband High-Efficiency DPA for 5G Micro Base Station

To meet the requirements of the 5G communication system, the Doherty power amplifier has become a research hotspot because of its peak-to-average ratio and high backoff efficiency. At the same time, with the continuous development of mobile communication technology, the traditional Doherty power amplifier has gradually been difficult to meet the needs due to its structural problems. On the one hand, due to the limitation of the 1/4 wavelength transmission line in the traditional Doherty power amplifier, it is difficult to achieve broadband. This paper uses the post-matching technology to remove the 1/4 wavelength transmission line to achieve broadband matching. On the other hand, in response to energy conservation and emission reduction, there is a growing demand to reduce power consumption in base stations. In this design, a harmonic suppression network is introduced at the output matching end to further improve the efficiency of the Doherty power amplifier. Finally, the asymmetric structure is introduced to further improve the efficiency of the power amplifier. Main and auxiliary power amplifier transistors select Cree CGH40010F and CGH40025 respectively. Based on the ADS simulation design and test, a broadband high-efficiency Doherty amplifier working in a 3.3~3.6 GHz band is designed for a 5G communication base station. The maximum saturated output power is 44.5 dBm and the drain efficiency is 67%~73%. When power fallback is 8 dB, the drain efficiency is 43%~51%.

Over Octave Hybrid Continuous Modes Power Amplifier Design Based on Modified Real Frequency Technique

In this paper, a design method for an over octave hybrid continuous mode power amplifier (PA) based on modified real frequency technique (MRFT) is proposed. The extended continuous class-F/F-1 modes greatly expand the design space, which provides the possibility of over octave design, the optimal impedances at internal current-generator (I-Gen) plane and package plane are investigated. Then a novel broadband matching network based on MRFT is presented for impedance match. To verify the proposed methodology, an over octave PA with radial stub is fabricated and measured. The PA achieves a bandwidth of 133% from 0.8 GHz to 4 GHz, over this frequency range, the drain efficiency is 58.3-68.7% and largesignal gain is greater than 9.6 dB.

Low-profile broadband microwave absorber based on magnetic coating and artificial electromagnetic structures

In order to realize electromagnetic stealth of large equipment, we propose a low-cost, mass-producible composite microwave absorber in this paper. The developed novel EM absorber comprises a pattern-impregnated honeycomb structure with the absorbent of carbon black (CB), a resistive frequency selective surface (FSS) embedded in polypropylene (PP) foam, and a mixture coating covered on a metal plane whose absorbent is flaky carbonyl iron (FCI). CB particles and FCI particles provide electrical and magnetic losses at the microscopic scale. Moreover, the subwavelength-scale artificial electromagnetic structure achieves broadband matching to free space by adjusting macroscopic geometric parameters. The consistency between measurements and simulations proves that the composite absorber achieves over 90% absorption ratio with a thickness of 8.3 mm from 2.06 to 18 GHz (corresponding to a fractional bandwidth of 158.9%). Additionally, this composite absorber possesses good mechanical property with a maximum uniaxial tensile stress of 67.43 MPa.

Quality factor based transducer power gain expression

PurposeIn the literature, while designing broadband matching networks, transducer power gain (TPG) is used to measure the transferred power. Generally, in TPG expressions, load and back-end impedances of the matching network are used. This study aims to derive a new quality factor-based TPG expression.Design/methodology/approachIn deriving the new expression, narrowband L type-matching network design approach is used and the new expression in terms of back-end quality factor, load quality factor and output port quality factor is obtained. Then, a broadband-matching network design approach using the derived TPG expression is proposed.FindingsTwo broadband double-matching networks are designed by using the proposed design approach using the derived TPG expression. Performances of the designed-matching networks are compared with the performances of the matching networks designed by means of simplified real frequency technique which is a well-known technique in the literature, and it is shown that they are nearly the same.Originality/valueIn broadband-matching problems, generally an impedance-based TPG expression is used, and it must be satisfied by the designed broadband-matching networks. But, in the literature, there is no quality factor-based TPG expression that can be used in broadband-matching problems. So, this gap in the literature has been filled by this paper.

Design of a broadband GaN 12 W power amplifier

AbstractA compact broadband 12 W power amplifier with broadband matching networks is presented. Transistors connected in parallel are used to synthesize the high power. Input, interstage, and output matching networks are also properly designed to meet the requirement of the broadband application. The broadband high power amplifier (HPA) was fabricated using a 0.15‐μm gallium nitride (GaN) HEMT technology, with a maximum saturated measured output power of 43 dBm from 6 to 18 GHz. The measured power added efficiency exceeds 20% in the whole interested band. The proposed HPA also has a compact size of 3.1 mm × 2.96 mm.

A 211-to-263-GHz Dual-LC-Tank-Based Broadband Power Amplifier With 14.7-dBm P SAT and 16.4-dB Peak Gain in 130-nm SiGe BiCMOS

This article presents a broadband sub-terahertz (THz) power amplifier (PA) with a low-loss four-way power combiner. The proposed power combiner consists of an improved zero-degree combiner (ZDC) and a three-conductor Marchand balun simultaneously achieving broadband matching and power combining. The proposed three-conductor Marchand balun adopts a dual- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$LC$ </tex-math></inline-formula> tank technique by merging two resonators, and it can be equivalent to a transformer-based multi-resonating network. The power distribution is realized by one input power splitter generating two pairs of differential signals and two parallel 1-to-2 active power splitters. This hybrid distribution driving network further enhances efficiency and power gain. Based on these improvements, a high-output-power sub-THz PA with superior efficiency has been fabricated in the 130-nm SiGe bipolar complementary metal oxide silicon field effect transistor (BiCMOS) technology. The three-stage PA achieves a peak power gain of 16.4 dB, 3-dB small-signal gain bandwidth of 52 GHz from 211 to 263 GHz, a measured maximum saturated output power of 14.7 dBm at 224 GHz, and a peak power-added efficiency (PAE) of 3.13% at 220 GHz. The folded input splitter and extremely compact power combining methodology lead to a core area of 770 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}\,\,\times \,\,280\,\,\mu \text{m}$ </tex-math></inline-formula> .

Broadband Matching of Patch-Antenna for Geolocation

The article presents the study results of the possibilities of expanding the working frequency band of a patch antenna , due to the broadband matching . As a systematic approach , a generalized Darlington method is proposed using flexible approximating functions with increased variable properties . These properties are necessary for the solvability of the system of restrictions on the agreement limits . The results of synthesis by the generalized Darlington method using flexible approximations provide a matching band of 10 %, but have an increased s ensitivity of the values of concentrated elements . A synthesis technique in a distributed element basis is also presented . In the synthesis of a matching chain on distributed elements , the Richards transform for homogeneous microstrip lines is used . A comparison of theoretical and experimental results of antenna matching is presented . Synthesis on distributed elements provided a 17 % band with a minimum number of matching elements . The synthesis technique in the distributed element basis can be used to match a wide class of vibrator and slot antennas , the dimensions of which are multiples of a wavelength quarter .

Neck-embedded acoustic meta-liner for the broadband sound-absorbing under the grazing flow with a wide speed range

Acoustic liners are the most commonly used dissipative muffler for aero-engines but remain a challenge to design a broadband acoustic liner under the grazing flow. In this work, a novel neck-embedded meta-liner is proposed for the broadband sound-absorbing under the grazing flow with a wide speed range. The meta-liner is composed of many neck-embedded Helmholtz Resonators, and the idea of bending the subsequent cavity is introduced to improve low-frequency sound absorption performance. The acoustic impedance model of the meta-liner with neck-embedded slit is first detailly established by analyzing the acoustic characteristics of the equivalent elliptical pipe and using the matrix transfer method. Then by designing the local coupling between channels, efficient broadband impedance modulation and broadband matching with air impedance under grazing flow conditions are realized. The proposed meta-liner exhibits the excellent sound attenuation capacity in the frequency domain of 500–3000 Hz under the grazing flow speeds from 0 m s−1 to 98 m s−1 and the sound absorption performance is greatly boosted compared with the traditional Double- Degree-Of-Freedom liner. Features mentioned above have been verified numerically and in a series of comparative experiments. Besides, the thickness of the meta-liner is only 50 mm. Our work provides a possible design reference for the new generation of acoustic liners and has potential applications in noise reduction engineering.

A Broadband Ka-Band Waveguide Magic-T With Compact Inner Ridge Matching

In this letter, a broadband waveguide magic-T with compact size is presented. A grounded suspended stripline has been used to obtain broadband isolation characteristics and increase power capacity. The inner ridge-matching structure is used to achieve broadband matching. The method and design process of the demonstrated magic-T are described in detail. The measured 15-dB bandwidth is about 30.3%, almost for waveguide BJ-320 waveguide operating bandwidth. The measured isolation between sum and deference ports is above 37.5 dB; 20-dB measured isolation is achieved between collinear ports. The measured and simulated results are in good agreement. It has advantages in high-power applications.