Dual-band Matching Research Articles

Dual-Band Matching Networks Using a Combination of Microstrip Lines and Active Switching Components

Active switching components are employed to propose a novel compact dual-band matching network (MN) with an adapted frequency in this paper. The design method involves the integration of active switching devices, stepped impedance resonator (SIR), and microstrip transmission line into the frequency response of a dual-band MNs. The PIN diode is employed as an active switching device in the proposed structure to increase the bandwidth of the MNs and attain the desired frequency. The dual-band MNs that are being proposed are fabricated and designed on the Rogers RO4350B substrate for use in Wireless Local Area Networks (WLANs). The simulation results demonstrate a high degree of congruence with the measurements. The maximal insertion losses and return losses in the first band are -1.3 and -24 dB, respectively. In the second band, they are -2.2 and -20.69 dB. The primary benefits of the proposed dual-band MNs are their high attenuation between two passbands, frequency matching capability, suitable return loss, and low insertion loss.

Dual-band low-power RF-to-DC signal converter circuits for energy harvesting

This article presents dual-band low-power, high-sensitive radio-frequency (RF)-to-direct current (DC) signal converter circuits, operating at 2.45 and 5.5 GHz bands, for radio frequency energy harvesting applications. In particular, it focuses on the lumped element and microstrip transmission line model circuits. The lumped element RF-to-DC converter circuit is composed of a dual-band impedance matching circuit, voltage-doubler rectifier, and DC-pass filter with a resistive load of 5 kΩ. This converter circuit gives a DC output voltage of 48 mV at 2.45 GHz and 25 mV at 5.5 GHz on −25 dBm input power. Maximum conversion efficiency is 47% at the 2.45 GHz band and 27% at the 5.5 GHz band when the input power is set to −10 dBm. Circuit design steps, matching conditions, performance parameters, and so on, are presented using Advanced Design System simulation. To validate the concept of the lumped element model, a microstrip transmission line RF-to-DC converter model is simulated and fabricated. It also composes of a dual-band matching network, voltage-doubler, and DC-pass filter with a load resistance of 5 kΩ. At a low input power of −18 dBm, it gives an output voltage of 21 mV in measurement. An appropriate match between the simulation and measurement is noted.

Efficient rectifier circuit operating at N78 and N79 sub-6 GHz 5G bands for microwave energy-harvesting and power transfer applications

Abstract The microwave energy-harvesting (MEH) and microwave power transfer (MPT) technologies have become the most emerging areas of research nowadays. The microwave rectifier circuit is the bottleneck of both the MEH and MPT systems. The efficiency of the system depends on the power conversion efficiency (PCE) of the rectifier. Due to the recent advancement of the fifth-generation communication system, it is desirable to propose an efficient rectifier operating at sub-6 GHz 5G bands. A dual-band rectifier circuit is designed and demonstrated for MEH/MPT purposes, specifically at sub-6 GHz 5G frequency bands. The dual-band matching is achieved by using a stepped impedance transmission line. The rectifier covers N78 (3.3–3.6 GHz) and N79 (4.8–5.0 GHz) bands. Peak PCE of 67.6% @ 3.5 GHz and 56.8% @ 4.9 GHz are achieved. For validation purpose, the rectifier is fabricated and characterized and measured results show good agreement with simulated results.

Multiband Impedance Matching Using Microstrip-Embedded MTM-EBGs

This work investigates a general method of multiband impedance matching using a double-stub tuner (DST) loaded with metamaterial-based electromagnetic bandgap structures (MTM-EBGs). MTM-EBGs are uniplanar and fully printable and can be embedded directly into microstrip (MS) stubs to imbue them with designable electrical lengths at two or more harmonically unrelated frequencies, without increasing the stub footprint. Combinations of these stubs, inspired by the DST, can produce multiband impedance matching to arbitrary, complex, and frequency-dependent loads. A dual-band matching network is first presented with this method, and a general design procedure is developed to match at two desired frequencies while maximizing bandwidth. Matching bandwidths of 44.4% and 22.1% around 2.4 and 5.8 GHz are observed. Next, a tri-band matching network is designed and fabricated for operation at 2.4/3.6/5.8 GHz, again following a general and well-established design procedure and presenting bandwidths of 16.8%/6.6%/18.3% around the three operating frequencies, respectively. The resulting circuits are uniplanar and compact, requiring a similar footprint to that of a single-band DST, and the matching networks are designed to ensure that dissipative losses in the matched bands are minimized. In all cases, measurement results of the uniplanar devices show excellent agreement with simulations.

A Compact Low-Loss Reflection-Type Harmonic Transponder for Battery-Less RFID Sensors Based on Harmonic Backscattering

This study presents a compact reflection-type harmonic transponder with a wide input power range for battery-less radio frequency identification (RFID) sensors based on harmonic backscattering. Miniaturizing the circuit size of conventional harmonic transponders is difficult because the input and output matching stages are configured separately, and two antennas are used for each port. The proposed harmonic transponder based on a dual-band matching network matches the load simultaneously at the fundamental and second harmonic frequencies over a wide input power range, thus enhancing the conversion gain (CG) with a compact size. For verification, the proposed transponder is implemented in a compact size with dimensions of 19 mm × 17.8 mm. The measured CG of the implemented transponder is maintained at over −10 dB in the wide input power range of −6.4 dBm to 10.6 dBm at 2.45 GHz. Th e harmonic transponder is configured with a dual-band chip antenna and measured in free space to verify whether it is suitable for battery-less RFID sensors. The measured detectable effective distance to the proposed circuit is 6.3 m in free space, with an equivalent isotropically radiated power of 42.6 dBm.

A 201- and 283-GHz Dual-Band Amplifier in 65-Nm CMOS Adopting Dual-Frequency $G_{\max }$-Core With Dual-Band Matching

This work reports a concurrent dual-band amplifier with an extensive spacing between the two bands by adopting a proposed dual-frequency maximum achievable gain ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$G_{max}$</tex-math></inline-formula> ) core with a dual-band matching. The proposed dual-frequency <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$G_{max}$</tex-math></inline-formula> -core can expand the difference between the two target frequencies by focusing on satisfying dominant gain-boosting condition and adopting a linear, lossy, and reciprocal based design approach. Implemented in a 65 nm CMOS process, a 5-stage dual-band amplifier shows a peak power gain of 23.6 and 13.7 dB, 3 dB bandwidth of 5 and 17 GHz, saturated output power ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$P_{sat}$</tex-math></inline-formula> ) of -1.2 and -2.2 dBm, and peak power added efficiency (PAE) of 2.1 and 1.5 % at 201 and 283 GHz, respectively, while consuming a DC power of 34.5 mW. The proposed amplifier is the first demonstration of the concurrent dual-band amplifier operating at G- (140-220 GHz) and H- (220-325 GHz) bands.

A 5.5/12.5‐GHz concurrent dual‐band power amplifier MMIC in 0.25 μm GaAs technology

A concurrent 5.5/12.5-GHz dual-band power amplifier (PA) is designed and implemented in a 0.25 μm GaAs pseudomorphic high electron mobility transistor process. The PA is composed of two stages and adopts LC parallel and series networks for dual-band matching. The efficiency of the PA is improved by lowering the drain voltage of the driver stage. Measurement results show that the proposed PA features the maximum small-signal gain of 17.1 and 15.6 dB, the maximum output power of 24.9 and 24.5 dBm, and peak power-added efficiency (PAE) of 35.5% and 35% at 5.5 and 12.5 GHz, respectively. The PA consumes a total DC of 73 mA, and its power consumption is 503 mW. The chip size of the PA is 1.4 × 1.3 mm2 including all testing pads.

Dual-Broadband Impedance Converter Based on Multiedge Frequency Matching Technique

In this letter, the dual-broadband impedance converter based on multiedge frequency matching techniques is presented. The proposed multiedge frequency matching method can realize the required impedance transformation at more than two frequency points, which makes it possible to break through the bottleneck of narrow band response in a scenario of conventional dual-band matching. A set of equations are derived from the transmission line theory, and then the design parameters of this dual-broadband converter can be easily solved. Besides, the proposed converter has the advantages of adjustable bandwidth at individual passband and high out of band rejection. The measurement results of the fabricated dual-broadband converter show good agreements with the simulations, which confirm the feasibility of the proposed design techniques. Specifically, the reflection coefficients ${S}_{11}$ are less than −15 dB at a passband of 0.83–1.32 GHz and 2.04–2.48 GHz.

Dual-Band Dual-Mode Textile Antenna/Rectenna for Simultaneous Wireless Information and Power Transfer (SWIPT)

This article presents a textile antenna for dual-band simultaneous wireless information and power transfer (SWIPT). The antenna operates as a 2.4 GHz off-body communications antenna and a sub-1 GHz (785–875 MHz) broad-beam rectenna. Incorporated within the broadside microstrip antenna is a high-impedance rectenna for sub-1 GHz power harvesting. Utilizing antenna-rectifier co-design, the rectenna eliminates the rectifier matching network. The textile antenna is fabricated on a felt substrate and utilizes conductive fabrics for the antenna. At 2.4 GHz, the antenna achieves a realized gain of 7.2 dBi on a body phantom and a minimum radiation efficiency of 63%, with and without the rectifier. The rectenna achieves a best-in-class RF to dc efficiency of 62% from 0.8 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{W}$ </tex-math></inline-formula> /cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , representing over 25% improvement over state-of-the-art textile rectennas and demonstrating that SWIPT does not detrimentally affect the energy harvesting or communications performance. The antenna/rectenna occupies an electrically small area of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.213\times 0.19\,\,\lambda ^{2}_{0}$ </tex-math></inline-formula> . This antenna is the first dual-band, dual-mode antenna demonstrated on textiles for SWIPT applications and the first dual-band matching network-free SWIPT rectenna.

Efficient Dual-Band Rectifier Using Stepped Impedance Stub Matching Network for Wireless Energy Harvesting

This letter presents an efficient dual-band rectifier using stepped impedance stub matching circuit. Theoretical analysis of the dual-band impedance matching circuit comprising a stepped impedance stub is carried out, which plays a key role in designing the resultant dual-band rectifier. The proposed dual-band matching circuit can achieve wide frequency ratio which is analyzed and predicted by simulation. For demonstration, a dual-band rectifier working at 0.915 and 2.45 GHz is fabricated with dimensions of 21.47 mm ×18.93 mm. The measured results show that with a 1500 Ω load, the maximum efficiencies of the rectifier reach 74% and 73% at 0.915 and 2.45 GHz, respectively. Due to the simple but efficient structure of the dual-band matching network, the dual-band rectifier in this work exhibits merits of compact size and high efficiency.

Design and analysis of a 1.1 and 2.4 GHz concurrent dual-band low noise amplifier for multiband radios

This paper presents the design and implementation of a dual-band low noise amplifier (DBLNA) operating at 1.1 GHz and 2.4 GHz. The DBLNA employs a second-order dual-band matching network, which is designed using the proposed impedance and frequency transformation technique. The DBLNA has two stages in cascade topology for its high output impedance and high voltage gain. Modified output load is designed to optimize interference rejection. The implemented circuit is fabricated as a microwave integrated circuit (MIC) on the FR-4 substrate. The designed DBLNA achieves a very high measured voltage gain of 24.4 dB and 20.1 dB at 1.1 GHz and 2.4 GHz, respectively. The measured NF of the DBLNA is 2.6 dB and 3 dB at 1.1 GHz and 2.4 GHz, respectively. The interference rejection between passbands at 1.6 GHz is 53.2 dB and stopband rejection ratio is 40.4 dB. The LNA consumes 108 mW from a 3 V supply. The measured P1dB performance is −10 dBm and −5.1 dBm at 1.1 GHz and 2.4 GHz, respectively.

Analysis of dual-band matching of an ends-fed dipole-like antenna and a coaxial line

The problem of dual/multi-band radiation of a single-body antenna is of a great topicality today when there is a continuing development of wireless communications both for civil and military purposes. The estimation of dual-band performance of endsfed dipole-like radiator, in particular, its matching with a standard purely active resistance coaxial line is given in the paper. The focus was on stating the necessary conditions and requirements on the geometric sizes of the structure under investigation and the frequency range it have to be analyzed through. It is also considered how to decrease amount of calculations needed at the starting stage of the antenna designing that includes the exact analytical approaches for near field calculations. This decrease is based on the difference in the impact the parameters under consideration have on the antenna input impedance. For the crucial electrodynamics characteristics calculations the induced electromotive forces (EMF) method is used, which has established itself as one of the most convenient in this field.

Design and Performance Prediction of a Dual-Band Coupled-Fed Dipole Array Antenna for PCL Systems in the VHF Band

This article proposes the design of a dual-band coupled-fed dipole antenna for passive coherent location (PCL) systems in the very high frequency (VHF) band. The proposed indirect coupled feed mechanism, which is often employed in microstrip patch antennas, is first applied to VHF band dipole elements for dual-band matching. To confirm the effectiveness of the proposed design, we fabricate the coupled-fed dipole element and measure antenna characteristics, such as the voltage standing wave ratio (VSWR) and the antenna gain. The proposed antenna element is then applied to an eight-element circular array to form the reference and surveillance beams for PCL systems. Finally, the target location is estimated by constructing amplitude-range doppler (ARD) maps for one frequency modulation (FM) and two terrain digital multimedia broadcasting (T-DMB) illuminators in the Seoul-Gyunggi urban area. The results confirm that the proposed element is suitable for dual-band PCL systems in the VHF band compared to a conventional dipole antenna.

A Compact Dual-Band Rectenna for GSM900 and GSM1800 Energy Harvesting

This paper presents a compact dual-band rectenna for GSM900 and GSM1800 energy harvesting. The monopole antenna consists of a longer bent Koch fractal element for GSM900 band and a shorter radiation element for GSM1800. The rectifier is composed of a multisection dual-band matching network, two rectifying branches, and filter networks. Measured peak efficiency of the proposed rectenna is 62% at 0.88 GHz 15.9 μW/cm2 and 50% at 1.85 GHz 19.1 μW/cm2, respectively. When the rectenna is 25 m away from a cellular base station, measurement result shows that the harvested power is able to power a batteryless LCD watch and achieve 1.275 V output voltage. The proposed rectenna is compact, efficient, low cost, and easy to fabricate, and it is suitable for RF energy harvesting and various wireless communication scenarios.

A transmission line decoupling technique for enhancement of port isolation of dual-band MIMO antennas

In this paper, a transmission line decoupling network (TLDN) technique is presented to enhance the isolation of a dual-band multiple input and multiple output (MIMO) antenna. The MIMO antenna with enhanced isolation is designed by the following steps: Firstly, each port of an initial 2-port MIMO antenna is connected with an admittance transformer formed by two transmission line sections. The length and the width of the admittance transformer are designed to retrieve mutual admittance between ports having only imaginary part. The two ports are then connected in parallel electrically with the proposed TLDN to cancel the resultant imaginary mutual admittance. At the final stage, a simple dual-band matching network is added to each port to improve matching performance. The proposed method is applied to two designs of dual-band printed MIMO antenna working at 2.45 GHz/5.25 GHz and 1.8 GHz/3.5 GHz. For the purpose of verification, the two designs were fabricated and measured. The measured results are in good agreement with the simulation ones. Both designs yielded a high isolation, low envelop correlation coefficient, simple structures for design and fabrication. These features demonstrated the feasibility of the technique in implementing MIMO antennas.

A Precise Harmonic Control Technique for High Efficiency Concurrent Dual-Band Continuous Class-F Power Amplifier

In this paper, a design approach for a high-efficiency concurrent dual-band power amplifier (PA) with precise harmonic control up to third order is proposed. With the precise harmonic control approach, the high-efficiency performance of the PA can be improved at two arbitrary wide interval frequencies. Based on the inherent impedance matching flexibility of the continuous Class-F (CCF) operating mode, the design spaces of fundamental and harmonic impedances of the PA are largely expanded. The optimal impedances of a CCF PA mode at the internal current-generator (I-gen) plane and package plane are investigated, respectively, and a novel dual-band matching network topology is designed to simultaneously present required load impedances at the fundamental and harmonic impedances of both operation frequencies. First, a harmonic control network is designed to control the harmonic impedances precisely for CCF operation. Then, the fundamental impedances are synthesized using the real frequency technique. To verify the validity of proposed methodology, a dual-band CCF PA operating at 2.6 and 3.5 GHz is designed, fabricated, and measured. The measurement results show that the peak drain efficiency is 76.7% with an output power 42.4 dBm at the lower band and 72.8% with an output power 41.1 dBm at the upper band.

Low-Profile Millimeter-Wave SIW Cavity-Backed Dual-Band Circularly Polarized Antenna

A single-fed low-profile millimeter-wave substrate-integrated waveguide (SIW) cavity-backed slot antenna for dual-band circular polarization (CP) applications is proposed. First, by employing two annular exponential slots carved on the surface of a circular SIW cavity, dual-band CP radiation is achieved. Two different modes, that is, the cavity mode and the surface mode, separately modulated by the cavity field distribution and the surface current, are investigated. They are utilized to achieve the dual-band CP radiation. Next, a two-order matching circuit using inductor windows is introduced to achieve dual-band matching at the low-profile antenna design with the help of the differential evolution method. Finally, for the dual-band CP application at 37.5 and 47.8 GHz, an antenna prototype is fabricated and its performance is evaluated. Simulation and measurement results agree very well.

Sub‐optimal matching method for dual‐band class‐J power amplifier using real frequency technique

A passive network possessing an input impedance which is positive real in nature poses difficulties with regard to obtaining an optimal impedance for power amplifiers (PAs) with two uncorrelated frequencies. In this context, this study presents a sub-optimal dual-band matching method via real frequency technique. Theoretical analysis is presented for voltage waveform with four independent variables and boundary conditions are given for not lower than zero region. To increase the possibility of acquiring a matching network, a sub-optimal but broad design space is defined according to acceptable performance. It is more practical to match dual-band or broadband PAs because a single fundamental harmonic impedance point could be corresponding to a set of the second harmonics in the new design space, vice versa. Thus, the sub-optimal solution space is bounded from region-to-region between the required fundamental and second harmonic impedances. An enhanced cost function based on driving point function that could better describe harmonic impedance mismatching degree is also proposed for harmonics control. Finally, a dual-band PA is designed to demonstrate the general matching method. The peak efficiency is about 70% and saturated output power is 41 dBm in both bands.

A Generic Tri-Band Matching Network

A scheme to achieve impedance matching at three arbitrary frequencies is presented. The proposed matching network is cascade of a dual-band matching network and a novel dual-to-tri-band transformer. Analysis of the proposed network provides closed form design equations that enable physically realizable solution owing to the presence of a free design variable. The presented theory is demonstrated through two example prototypes on Roger's RO4350B substrate. The obtained simulated and measured results clearly exhibit the potential of the proposed design.

Comments on “Novel Dual-Band Matching Network for Effective Design of Concurrent Dual-Band Power Amplifiers”

A novel dual-band matching network for concurrent dual-band power amplifiers has been proposed and discussed by Fu in January 2014. The first stage matching network effectively accomplished real-to-complex impedance transformation by utilizing a transmission line, a short-circuited stub and an open-circuited stub. However, the obtainment of the values of the electrical parameters are realized by tuning and observing Smith Chart, no analytical design methodology given. In this comment, rigorous design equations of the real-to-complex matching network are extracted, and two numerical instances are demonstrated for verification. Additionally, an error about the input impedance in original paper is corrected.