International Journal of RF and Microwave Computer-Aided Engineering最新文献

This paper presents a 28- and 38-GHz bandpass filter for 5G communication systems, which is implemented in an interdigital-coupling microstrip line structure on a Rogers RT5880 substrate. The main resonator is composed of two U-shaped units loaded with short cutoffs and stepped impedance stubs connected at the bottom of the U-shaped structure. The design is effectively tuned to work in the 28 and 38 GHz bands of 5G NR. The LC equivalent circuit of the filter is converted to a physical size of the lumped element by using planar microstrip technology for physical implementation; the suppression in the stop band is lower than −20 dB. The proposed bandpass filter is designed as a microstrip line structure, which can be easily matched with the next level components due to its planar structure. Therefore, it is easier to apply in 5G devices and is suitable for 5G n257 and n260 applications.

A quad-fed triband circularly polarized (CP) patch antenna based on three resonant modes is proposed in this paper. This antenna consists of a square patch loaded with an open cross slots, two pairs of arc slots, and four shorting pins. The acquisition of the three bands is attributed to the simultaneous excitation of TM₁₁ mode of circular patch, TM₁₀ mode of square patch, and the one-wavelength cross slot mode. The TM₁₁ mode of circular patch is excited by the cooperation of the arc slots and the shorting pins, while the loading of the open cross slot moves the TM₁₀ and TM₂₁ modes of the square patch to a higher frequency. Furthermore, the introduction of the arc slots improves the impedance matching of the one-wavelength cross slot mode. The equivalent circuit of the proposed quad-fed patch antenna is established, and its validity is verified. For implementing CP radiation with the same sense in all three bands, a sequential phase feed network is designed and cooperated with the antenna. In order to verify the design concept, an antenna prototype is fabricated and measured. The measured results show that the VSWR is less than 2 in 2.54–5.5 GHz, which can cover the three frequency bands of the proposed antenna. The AR bandwidths in three bands are 33.1%, 27.6%, and 8.6%, respectively. The peak RHCP gains in the three bands are 5, 9.9, and 4.1 dBic, respectively. The profile is 0.032λ₀ (λ₀ is the wavelength in the free space at 3.2 GHz).

This paper presents a new small, low-profile planar triple-band microstrip antenna for WLAN/WiMAX and 5G applications. Nowadays, various wireless services are being integrated into a single device, so these devices require multiband resonant antennas to maintain their compact and portable size. Therefore, the aim of current research was to combine WLAN WiMAX and 5G communication standards together into a single wireless device by designing an antenna that can stimulate triple-band operation. The proposed antenna consists of circular-shaped rectangular slotted radiator encircled by a rectangular ring and a defected ground plane. The designed antenna has a compact size of 20 × 32 mm² (0.16λ₀ × 0.256λ₀). The optimum dimensions were obtained using parametric studies of the key parameters of the antenna. The proposed antenna offers three different bands—I 2.3–2.70, II 3.2–3.92, and III 5.1–5.9 GHz, which clearly covers the entire WLAN (2.4/5.2/5.8 GHz), WiMAX (2.5/3.5/5.5), and 5G bands. Finally, a proposed antenna was built and studied experimentally to verify the design concept as well as validate the simulation results. The good agreement of the simulation results with the measured results proved that the antenna can simultaneously operate on WLAN (2.4/5.2/5.8 GHz), WiMAX (2.5/3.5/5.5 GHz), and 5G frequency bands. This antenna is a suitable candidate for a device that can be used for these three services simultaneously.

A manifold-coupled multiplexer comprising substrate integrated waveguide (SIW)–spoof surface plasmon polariton (SSPP) hybrid filters and a microstrip line network is proposed for Ka-band applications, achieving a compact profile and low insertion loss. The narrowband hybrid filter is designed by converging the cut-off frequencies of SIWs and SSPPs, which may avoid the high-order modes of the resonant filters, and two SSPP slots are chosen for filter miniaturization without significantly sacrificing the cut-off response. A short taper is designed to connect the hybrid filter and microstrip lines, and the microstrip line network is carefully optimized to match the manifold phase configuration with a compact size. A prototype is fabricated and characterized for demonstration. The experimental insertion loss is 2.10, 2.49, and 2.61 dB at 28.2, 29.7, and 31.2 GHz, respectively, and the corresponding 3 dB bandwidth is 4.1%, 4.7%, and 4.8%, respectively, showing a good match with the simulation. The reflection loss is larger than 10 dB from 27.8 to 31.4 GHz. Considering the promising out-of-band rejection of the hybrid filters, such a configuration should be suitable for multiplexers with large channel numbers and may find many applications in ultra-wideband and multifunctional communication systems.

M. He, J. Yun, B. Wang, X. Zhang, and X. Liao, “Compact Millimeter-Wave Antenna Array With Low Sidelobe Level for Vital Sign Monitoring Application,” International Journal of RF and Microwave Computer-Aided Engineering 2023, no. 1 (2023): 1–9: 10.1155/2023/6256889

In the article titled “Compact Millimeter-Wave Antenna Array With Low Sidelobe Level for Vital Sign Monitoring Application,” the authors Mengxue He and Jie Yun were incorrectly affiliated. The correct affiliation for these authors is as follows:

Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China

We apologize for this error.

A dual–dielectric resonator oscillator (DDRO) was previously introduced as a promising configuration for wireless power transfer (WPT), achieving a wireless power level of 13.07 dBm with a DC-to-RF efficiency of 19.50%. This work presents the design, simulation, and implementation of a single-port WPT system employing a parallel-feedback DDRO for increasing the output power level. The design incorporates a 7.5-GHz oscillator network featuring a class AB common-source power amplifier transistor integrated with a dielectric resonator (DR)–based WPT. By utilizing a parallel-feedback oscillator circuit, which enables efficient impedance matching through load-pull analysis and eliminates the need for a lossy termination at the end of the feed line, and optimizing the coupling structure for the transmitter DR, the output power level and the DC-to-RF conversion efficiency have been significantly improved. The implemented circuit delivers a measured wireless power level of 14.83 dBm, showing an improvement of approximately 2 dB, with a DC-to-RF efficiency of 36.85% at 7.5 GHz, while maintaining a transmission bandwidth of 150 MHz. This capability facilitates simultaneous transmission of both power and data over a single channel. The paper also presents an accurate model for design purposes and demonstrates validity of the model using our measurement results.

This paper introduces a compact dual-band band-pass filter using single multimode (TE₁₀₁, TE₁₀₂, TE₂₀₁, and TE₂₀₂) substrate-integrated waveguide (SIW) cavity with independent controllable fractional bandwidth (FBW) using metallic vias and slot perturbations. A via is placed at the center of the cavity, to shift the TE₁₀₁ mode towards the TE₁₀₂ mode which forms the Passband I with a center frequency (CF) of 16.2 GHz and a FBW of 1.71%. Two vias and slots are positioned and adjusted to shift the TE₂₀₁ mode and TE₂₀₂ mode, respectively, to achieve the Passband II with a CF of 19.1 GHz and an FBW of 3.09%. The measured insertion loss (IL) of the proposed filter is 1.8 dB for the Passband I and 1.9 dB for the Passband II.

In wireless telecommunication systems, the precise adjustment of the antenna direction has a direct effect on the quality of the received signal. In this article, a new routing algorithm is designed using the wireless energy harvesting (WEH) technology from electromagnetic waves to adjust the orientation of the receiver antenna. The algorithm is simulated for routing in TDD LTE cellular network at 2.35 GHz frequency. The proposed antenna in this article is a cross-dipole type with dual-polarization RHCP and LHCP, and its measured impedance bandwidths are 1.97–2.70 GHz at Port 1 and 1.96–2.72 GHz at Port 2. Also, 7.45 dBic peak gain and end-fire radiation capability of the proposed antenna are among the advantages of the automatic routing system. The proposed rectifier for WEH uses the voltage doubler technique. A new construction of microstrip elements has been used for the impedance matching network (IMN). The fabricated rectifier at 2.35 GHz can provide PCE = 52.8% at −0.5 dBm input power, which is suitable for WEH.

A printed MIMO antenna specifically designed for small satellite communication has been presented in this paper. The antenna is invented of two radiators resonating at millimeter-wave and constructed using Rogers’s RT duroid 5880. The design includes two identical octagonal patches with a diamond-shaped slot and having two quadrilateral notches. These elements are placed over a substrate and connected to a microstrip transmission line that embeds a quarter-wave transformer. To establish the effectiveness of the MIMO antenna being proposed, a comparative analysis is conducted between its simulated and experimental performance. Each radiator in the antenna setup includes partial ground, which forms the back layer of the substrate. The design is simulated on the CST tool, and measurements are conducted on a Rohde and Schwarz vector network analyzer. The obtained results show a favorable level of agreement with the simulated outcomes, validating the effectiveness of the proposed MIMO antenna. The antenna design offers exceptional features such as wide bandwidth, self-isolated, high gain, and a directional radiation pattern while also supporting a wide frequency band, making it an ideal choice for 28 GHz band applications. The performance of MIMO antennas in diversity can be determined using parameters such as envelope correlation coefficient (ECC), diversity gain (DG), and total active reflection coefficient (TARC). Satellite communication will be improved by implementing the suggested MIMO antenna through upgrading small satellite communication systems.

In the context of the rapid development of wireless body area network and ultra-wideband technology, this design puts forward a new structure of ultra-wideband flexible antenna. Its operating band is 1.22–8.82 GHz, with a maximum gain of 4.8 dBi. The antenna adopts a polyimide material with a relative dielectric constant of 3.5 and a thickness of 0.2 mm as the dielectric substrate. The overall size of the antenna is very small, measuring 0.15λ × 0.21λ at the lowest frequency of 1.22 GHz. In this paper, the influence of some antenna parameters on its performance, the influence of different bending conditions on the performance of the antenna, and the specific absorptivity of the antenna to the human body are discussed. In order to further explore the performance stability of the antenna, the performance of the antenna under right-angle bending is simulated and tested in this paper. Simulation results show that the antenna still has two frequency bands 1.22–2.58 GHz and 3.35–9.53 GHz under right-angle bending, which can still cover most of the commercial communication bands, and the measured results are in good agreement with the simulation results. Therefore, the antenna has strong adaptability and damage resistance and can be used in wearable equipment for military or emergency rescue.