Aiming at the efficient radiation simulation of anten-nas with dielectric slabs and spatial multiscale features, a discon-tinuous Galerkin (DG) scheme for the multi-region surface inte-gral equation is presented in this letter. Boundary lines between different materials can be handled independently without merging and reducing unknowns at the junction, which simplifies the cal-culation. Numerical experiments of different kinds of antennas are carried out to verify the accuracy and efficiency of the proposed method through comparisons.
Dual-circularly-polarized magneto-electric(ME) dipole for satellite system is proposed in the paper. The results indicate the design has the excellent results. The impedance bandwidth of the antenna is 10.7-14.9GHz, and the antenna's axial ratio bandwidth is about 32.8%. The results indicate that both polars have similar performance. The antenna has a size of 10.3mm*10.3mm*3.4mm, which is suitable for implementations in phased array. In order to improve performance of the antenna, the wide-angle impedance matching(WAIM) layer is used. Air hole is punched all around the WAIM in order to improve isolation between elements in the array.
A dual-band and dual-polarized antenna using metasurface for 5G application is proposed in this paper. The antenna has achieved excellent dual-band broadside radiation performance maintaining a low profile characteristic by introducing a dual-layer metasurface structure. The bandwidths of the proposed antenna are 13.9% (2.46-2.83GHz) and 14.4% (3.22-3.72GHz), whose overall size is 0.82λ0 × 0.82λ 0× 0.053λ0. For these dual operating bands, the antenna achieves high realized gains of 8.4-9.88dBi and 9.12-11.85dBi, respectively, with interport isolation over 40dB.
This paper proposes a 59–65 GHz, 10.58 % tuning range, -97.2 dBc/Hz@lMHz phase noise, 16 mW power consumption, 181.45 dBc/Hz@lMHz $\text{FoM}_{\mathrm{T}}$ , 0.052 mm 2 area frequency generator based on 20 GHz VCO and multiplied-by-three frequency multiplier with the technology of 40-nm and 1.1 V supply voltage. The major idea is to construct a 20 GHz VCO with good phase noise and use the theory of injection lock to attain 60 GHz output. Switching capacitors and stacked MOSFETs are used in VCO, and a fourth-order resonator is applied in the multiplier.
This paper presents an ultra-low power quartz crystal temperature-compensated real-time clock. By using a pulse injection oscillator (PIO) instead of a conventional Pierce oscillator, a multi-phase output is provided to improve digital compensation accuracy while reducing power consumption. The temperature compensation is achieved by dynamically selecting the multi-phase output of the PIO based on the lookup table data to offset the temperature drift, which improves the instantaneous compensation accuracy compared to the traditional digital frequency division-based method. An on-chip ring oscillator controlled by a proportional to absolute temperature current source using switched capacitor is implemented to obtain temperature information by counting its output frequency. Simulation based on the TSMC 65 nm CMOS process shows that the circuit has an absolute long-term compensation accuracy of 2.2 ppm and a total power consumption of 20.9 nW at typical operating conditions of 25°C and 0.6 V supply.
Neuro-transfer function (neuro-TF) methods are increasingly applied in the parametric modeling of microwave passive devices. Current neuro-TF methods based on poles/residues have the problem of poles/residues discontinuity when the geometry varies widely, and neuro-TF methods based on poles/zeros form require specific algorithms for ordering or poles/zeros matching. The neuro-TF method based on rational transfer functions proposed in recent years solves the above three problems simultaneously. The purpose of this paper is to apply the MOR-based neuro-TF method with rational transfer function to model a four-pole waveguide filter.
The development of an electromagnetic (EM) parametric model can be challenging when the geometrical parameters of the model differ significantly. To overcome this issue, a paper reviewed an automatic system algorithm that utilizes second-order derivative information. This method involves dividing the entire geometrical region based on its degree of smoothness, creating sub-regions for both flat and uneven areas. Each sub-region's geometrical parameters are treated as variables, and a neural network model is established to represent the sub-region, which is called the sub-model. However, moving from one sub-model to an adjacent one results in a different EM response at the boundary, causing multidimensional discontinuity. The paper proposes a solution to this problem, allowing for a continuous overall model.
In the sub-6G age, communication requires higher bandwidth for antennas. A low-profile wideband antenna based on multimode resonance has been created. By etching two slots on the rectangular patch, an additional resonance can be excited. The bandwidth and reflection coefficients of the antenna have been significantly improved by connecting a secondary radiation patch to the main radiator, consisting of two metal arms and connecting lines. Compared with traditional wideband antennas, the proposed antenna is compact and has a simpler structure. Finally, the proposed antenna was fabricated and tested to verify this design. The measured and simulated results are highly consistent, demonstrating a wide bandwidth of 19% and an average gain of 8.1dBi.
In this paper, a band-stop resonant cavity is designed based on the characteristics of transmission zeros generated by mutual suppression between different resonant modes in a multi-mode resonant cavity. By optimizing the size of the multi-mode resonant cavity, the position of the two transmission zeros generated by the two pairs of resonant modes is adjusted, and a band-stop resonant cavity with a stopband of 90.5 GHz-94.77 GHz is designed. Based on the band-stop resonator designed by the multi-mode resonator, a band-stop cavity filter with a band-stop band-width of 6.95 GHz (89.16GHz ~ 96.11 GHz) is designed by cascading and differentiating the two band-stop resonators.
In this paper, a flexible and miniaturized RFID strain sensor tag with chip is proposed for the detection of metal surface strain. The flexible miniature RFID tag is composed of a flexible substrate, tag microstrip antenna and RF chip. Its flexible substrate and small size makes it suitable for more application scenarios and reduces the cost of a single tag. The flexible RFID sensor tag is designed and the parameters are optimized firstly. Then, the strain detection performance of the tag is studied through numerical simulation. Finally, a quantitative detection approach of metal surface strain is proposed, which can realize the quantitative nondestructive and wireless detection for the metal component surface strain. The designed RFID strain sensor are expected to be applied in the surface strain monitoring for the bearing in the EEF bogie of the high-speed train as well as the interlaminar stress in hydrogen storage tank as well.
This article presents a novel low-power multi-band mixing frequency synthesizer for FDD System. The synthesizer can provide local oscillation signals for both TX and RX simultaneously with only one phase-locked loop (PLL). By selecting the spacing frequency between the uplink and downlink as its reference, plus a notch filter removing strong spur component, this PLL achieves lower power consumption and smaller die area. The mixing frequency synthesizer is fabricated in 65 nm CMOS process with an area of 0.571 mm2, The test results show that the proposed synthesizer achieves a 3.3-3.66 GHz frequency tuning range with the out-of-band PN of -114.9 dBc/Hz at 1 MHz offset from a 3.42 GHz carrier. And the reference spur is measured to be -50.16 dBc at 180 MHz offset. The entire mixing frequency synthesizer consumes 7.2 mW at the 1.2 V supply voltage with 4.15 mW associated with VCO.
A millimeter-wave dual-band dual-polarized shared-aperture antenna for satellite communication applications is proposed in this study. A low-band (LB) dielectric resonator element is placed on top of a high-band (HB) patch element in the proposed antenna. The LB unit's radiator uses a non-metallic cube dielectric resonator to minimize the impact of LB elements on HB element radiation performance, allowing radiation from HB elements to flow through LB elements without degradation. A dual-band dual-polarized shared-aperture antenna working at 25.87-28.09 GHz (LB) and 28.44-32.07 GHz (HB) is constructed and simulated. The proposed antenna has a lower profile coverage of only 1.143 mm (0.103 λ L , λ L is the working wavelength at the center frequency of LB).
The electromagnetic environment in airport is very complex. glide-slope localizer and localizer are part of the Instrument Landing System. They cooperate with the airborne receiver to provide space guidance for the aircraft during the approach and landing process. The End-around Taxiway Screen built at the end of the airport runway will cause interference to the electromagnetic environment of the airport and have a certain impact on the aircraft approach and landing process. In this paper, the model of glide-slope localizer and localizer antenna array and the model of visual shield are established. The coupling effect of End-around Taxiway Screen (EAT Screen) and localizer antenna array is analyzed by image method. The hybrid simulation method of finite element and bouncing ray method is used to improve the simulation efficiency, which provides technical methods for the research of civil aviation electromagnetic compatibility and can provide support for the planning and construction of End-Around Taxiway Screen.
This work presents the design of a four-order bandpass filter (BPF) for W-band applications using integrated passive device (IPD) technology. A coupling architecture with three configurable transmission zeros is employed to improve the passband selectivity. Additionally, combining folded stub loaded resonators (SLRs) and stacking resonators vertically reduces the overall foot-print of the circuit. The simulation results show that the suggested BPF, which operates at 95 GHz, has a number of benefits including low insertion loss, excellent selectivity, small size, and convenient to be integrated. The compact size and easy integration of the proposed BPF render it a compelling option for upcoming wireless communication systems.
In this paper, a fully integrated GaN Doherty power amplifier for WLAN 802.11ax application is presented. The output match network is realized by T-type three microline to decrease insert loss and increase efficiency. The PA is fabricated in a 0.25um GaN HEMT technology with a die size of 2.7mm*2mm. The DPA is designed at 6.4~7.2 GHz with a 28V supply voltage. The DPA can obtain a large signal gain over 20dB, >30% DE at 10-dB PBO, an ACPR of -27.7 dBc without DPD, and -52.37 dBc with DPD at an average output power of 27 dBm with a 100 MHz 64-QAM modulation signal.
This paper introduces an X-band switchless class-G (SLCG) power amplifier fabricated in 0.15-µm GaN HEMT technology. The switchless Class-G is adopted to improve the output back-off efficiency without additional bandwidth limitation. The measurement results in 8.2-9.2 GHz show that the PA achieves a maximum output power of 37.2 dBm and an average power-added efficiency of 22% at the 6-dB output back-off. The ACPR after digital pre-distortion is better than -48 dBc for a 20MHz long-term evolution (LTE) signal with a 7.5 dB PAPR.
This paper presents a terahertz wideband on-chip antenna in TSMC 65nm process. The characteristic mode analysis (CMA) is used to guide the antenna design, and the wideband performance of the antenna is achieved by selecting the appropriate characteristic modes. A metal plane is added under the antenna substrate to reflect the electromagnetic wave leaked to the substrate and improve the antenna efficiency. The overall area of the antenna is $800\text{um}\times 800\text{um}$ . The simulation results show that the antenna achieves the maximum gain of 7.6dBi at 300GHz, a 110GHz 3dB bandwidth (BW) from 280GHz–383GHz, and a 73GHz–10dB impedance bandwidth from 260GHz- 325GHz. The maximum radiation efficiency is 45% at 306GHz.
This paper presents a compact V-band low noise amplifier (LNA) employed stability enhancement and optimized transformer-based matching technique. The LNA is composed of two pseudo-difference common-source stages structure. Each stage adopts the neutralizing capacitor technology to optimize the noise figure and employ the transformer-matching network for a compact footprint. The proposed LNA is implemented in a 65-nm CMOS technology and consume a DC power of 38 mW at a sup-ply of 1.2 V. The amplifier achieves a 23.3 dB gain with a 3-dB bandwidth between 48.3 and 55.8 GHz. At 52 GHz, the optimum noise figure (NF) is 3.4 dB and is below than 3.65 dB over the whole band. Thanks to the compact transformer-based matching network, the LNA achieves a core chip size of only 0.09 mm 2 ,
This paper presents an ultra-low-cost L-band spread spectrum GNSS signal generator. Conventional SDR-based GNSS signal generators are expensive and they require a standalone computer to generate the baseband signal. The pro-posed ultra-low-cost GNSS signal generator adopts high-order harmonic mixing techniques to greatly simplify the LO chain design and uses an I2S peripheral on the micro controller to gen-erate the spread spectrum signal stream. Due to the extremely lean architecture, the entire system contains only 3 active devices and is fairly low-cost. A novel bit operation-based 1-bit quantization method is proposed to generate the required bitstream.
