Aeu-International Journal of Electronics and Communications最新文献

In this paper, a new voltage-mode second-order multifunction filter with three current feedback operational amplifiers is developed. This circuit generates low-pass filter, band-pass filter (BPF), inverting-type BPF, notch filter, and all-pass filter (APF) responses with all gains. It has high input and low output impedances for all the filter responses. It also has the advantage of grounded two capacitors, which is essential for integrated circuit technology. It has orthogonally controllable features for all the filter responses except the APF one. However, one passive element matching condition is needed to obtain an APF response. Many simulations are carried out via the SPICE program, where 0.13 µm technology parameters are utilized. Furthermore, a few experiments are performed using the AD844s to see the performance of the developed filter in practice.

Cross-eye jamming is a technique used for deceiving the angle measurement of monopulse radars. Long baseline (i.e., long spacing of jammer antennas) is an attractive option for cross-eye jammers, which can increase the angular error for monopulse radars. Phase error is a key factor restricting the performance of cross-eye jammers. In this paper, one of the sources of the phase error, i.e., local oscillator (LO) phase noise, is analyzed for a long-baseline cross-eye jammer. The effect of LO phase noise on the jamming performance is revealed for the first time. Additionally, the tolerance requirements for the LO phase noise of long-baseline cross-eye jammers are determined through theoretical analyses. Finally, the theoretical analyses are verified by Monte Carlo simulations. The research results can provide theoretical insights for system design and component selection for cross-eye jammers.

In this research, a novel high permittivity ceramic silicone composite substrate (HPCSCS) based antenna design is proposed for RF energy harvesting (RFEH). The HPCSCS is prepared using high-permittivity barium titanate (BaTiO₃) ceramic powder mixed with RTV silicone sealant (RTVSS) which possesses a high permittivity value of 11.9. Five different antenna designs were simulated in CST software and one design has been finalized based on design geometry, bandwidth, gain, and reflection coefficient. Moreover, the proposed antenna design is optimized with the addition of a coplanar waveguide. The designed antenna has a thickness of 0.06 mm and provides a wide operating band range from 0.7 GHz to 3 GHz. It provides a reflection coefficient of –32 dB and a positive gain of 1.84 dB at the operating frequency of 2.66 GHz demonstrating the excellent wide bandwidth of 885 MHz. A prototype of the antenna is fabricated and mounted on an HPCSCS for measurement through a vector network analyzer with a good match between the simulated and measured results. The rectenna system (antenna + rectifier) for RFEH has been developed and tested, which achieved a maximum rectifier conversion efficiency of 57 % at 0 dBm and produced a maximum output voltage of 1.35 V at 0 dBm.

This paper describes the optimal design and analysis of compact multiband Hybrid Fractal Antenna using Invasive Weed Optimization (HFAIWO). The configured structure involves the fusion of Minkowski, Sierpinski carpet and Giuseppe Peano in a coherent manner. The two-iterative conglomerated fractal antenna is realized physically by considering FR4 epoxy material (dielectric constant, ε_r = 4.4 and mass density = 1,900 kg/m³). The volumetric dimensions of the fabricated prototype are 36 x 36 x 1.6 mm³. In the designing process, the geometrical descriptors, namely, feedline width ‘W_F’ and ground plane dimension ‘L_G’ are optimized specifically using Invasive Weed Optimization (IWO) and Harmony Search Algorithm (HSA) strategies. The optimal solution is searched by changing the descriptor values under a set of practical constraints. The examined values of ‘W_F’ and ‘L_G’ using IWO and HSA are 3 and 31 mm, and 2.6 and 28.7 mm, respectively. Comparative results reveal that IWO offers superior solution quality and convergence than HSA. Afterwards, experimentation of the Projected HFAIWO is done to justify the recommended fractal hybridization approach. Measurements reveal that for VSWR ≤ 2, the fabricated structure produces nine resonance points (1.84, 3.99, 5.15, 5.55, 6.30, 6.58, 8.00, 9.29, and 12.01 GHz) with appreciable gain values. At the respective resonance points, the −10 dB impedance bandwidth is 3.9 %, 3.1 %, 2.1 %, 2.2 %, 1.4 %, 1.2 %, 6.9 %, 1.2 %, and 12.23 %. The provided radiation patterns are arbitrary bidirectional/omnidirectional. By applying the above-said approaches, the radiator size is reduced by 54 %. Importantly, the constructed structure covers two important bands i.e. 1.84 GHz (GSM 1800 band, downlink) and 5.55 GHz (WLAN (Lower) 5.150–5.725 GHz) associated with energy harvesting applications. The practical outcomes suggest that the introduced prototype is a proficient candidate for energy harvesting systems, Satellite communication for downlink, Long range tracking, Battlefield surveillance, Digital broadcast satellite service, Weather Radar, and Maritime navigation radar.

A compact low loss wideband diplexer is introduced by using stacked 2D and 3D structures through 3D advanced packaging and through glass vias (TGV). An inductor is designed by using stacked 2D and 3D structures to reduce the coupling effect between adjacent 2D inductors located in the same layer. It can greatly improve the Q factor yet minimize the chip size. This low loss, small size diplexer is developed by virtue of a modified topology and the proposed stacked 2D and 3D structures. The designed diplexer with a compact size of 1.6 mm × 0.8 mm × 0.25 mm is fabricated using 3D glass-based advanced packaging technology and measured by on-wafer probing. The measured results indicate that it achieves an insertion loss less than 0.8 dB and 0.9 dB and an isolation better than 20 dB and 17.5 dB in the bands of 0.699 GHz-0.960 GHz and 1.71 GHz-2.69 GHz, respectively. In comparison with the previously reported designs, the proposed diplexer shows the superior advantages of smaller size and lower insertion loss.

This paper presents a novel multibeam filtering antenna array based on a compact 3 × 3 Nolen matrix integrated with HRR filters for solar observations. The design facilitates the simultaneous recording of solar radio flux density and sky background flux density, streamlining calibration processes. The use of stub-loaded transmission line (SLTL) couplers achieves a significant 43.4% reduction in the size of the Nolen matrix, enhancing compactness. The hairpin ring resonator (HRR) filter with two transmission zeros (TZs) is employed to ensure electromagnetic compatibility (EMC). Given the limitations of conventional manual design methods, the intelligent grey wolf algorithm (GWA) is adopted to optimize the physical parameters of the Nolen matrix layout, realizing rapid and accurate achievement of the desired performance. The $-6.2\pm 0.15$ dB transmission coefficient and 0°, −120°and $+120$°of output phase differences within 2° phase error are accomplished at 2.8 GHz. Finally, the proposed multibeam filtering antenna array is fabricated and measured to confirm its ability to generate the required three beams with filtering characteristics. The measured results have a good agreement with the simulated results.

This paper presents an LDO design tailored to the various power domains of CPUs. In contemporary CPU designs, different functional modules typically necessitate distinct voltage levels, thus requiring a flexible and adjustable power management approach. An LDO with an internally compensated super source follower (SSF) and a multi-zero-pole compensated loop stability is proposed. The SSF is used to reduce the output impedance of the LDO, enhancing its carry-under-load capability. The loop is then transformed into a multi-zero-pole system through Miller compensation, feed-forward compensation, and zero-pole tracking compensation techniques, enabling the LDO to achieve stability and reliability under different loads. The LDO proposed in this study was designed using a 110 nm CMOS process. The LDO can operate within a temperature range of −40–150 °C, with a low quiescent current of 57 μA. The power supply rejection ratio of the circuit is −22 dB at 1 MHz. When the load current jumps from 5 mA to 300 mA within 40 μs, the output voltage experiences an undershoot of 271 mV, an overshoot of 174 mV, and a maximum adjustment time of 100 μs. The load regulation is 0.00267 mV/mA, and the line regulation is 1 mV/V.

This work presents a novel resistorless memristor emulator circuit designed in both grounded and floating configurations. The grounded memristor consists of a Current-Controlled Current Conveyor Transconductance Amplifier (CC-CCTA) and a capacitor. On the other hand, a floating memristor includes a CC-CCTA and a capacitor, along with an additional Operational Transconductance Amplifier (OTA). These proposed emulators are electronically controllable owing to the internal structures of active elements. Theoretical analysis and simulation results have been obtained for the proposed designs. Simulation results have been conducted utilizing the LTspice program and TSMC 180 nm technology has been used for internal structures. In these results, the effects of the changing capacitor values, different frequencies, electronic tunability, reactions to temperature change, and pulse response have been investigated. Subsequently, a chaotic Jerk circuit has been implemented incorporating the proposed memristor emulator. The chaotic behavior of the floating memristor has been investigated using the LTspice simulation software.

Maximal ratio combining (MRC) and selection combining (SC) diversity techniques enhance wireless communication networks’ reliability by mitigating fading effects and improving the signal-to-noise ratio (SNR) at the receiver. Hence, these techniques have a crucial impact on reducing the bit error rate (BER) and increasing the capacity of wireless communication systems. This paper introduces new exact mathematical formulas for the distribution of instantaneous SNR, BER and channel capacity per unit bandwidth (CpUB) for L-branch MRC and SC diversity receivers in offset quadrature amplitude modulation-based filter bank multi-carrier (OQAM/FBMC) systems for 5G wireless communication. Additionally, new formulations for BER and CpUB using the semi-analytical method have been derived. These formulas consider the combined effects of non-linear distortion from a high-power amplifier (NLD-HPA), the Rayleigh fading channel, and impulsive noise (IN). Monte-Carlo computer simulations verify the validity and accuracy of the derived theoretical instantaneous SNR, BER and CpUB across OQAM/FBMC-MRC and OQAM/FBMC-SC diversity system parameters, such as the number of branches (L), the input back-off (IBO) of NLD-HPA, and IN. According to the results of simulation modeling and a comparative analysis of performance, the OQAM/FBMC-MRC diversity system tends to have better BER performance and CpUB compared to the OQAM/FBMA-SC system in all scenarios.

A square-shaped patch antenna with high-gain performance and polarization reconfigurability is introduced in this study. This antenna offers the unique capability of seamlessly transitioning between linear polarization (LP) and circular polarization (CP), expanding its versatility in various communication applications. The polarization flexibility is achieved through the strategic integration of two RF switches utilizing p-i-n diodes, strategically positioned within the square slot structure. Through meticulous optimization of the switch placement, the antenna is capable of generating both right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) patterns. Fabrication and testing of the prototype validate the efficacy of the design, showcasing excellent agreement between simulated and measured results. Notably, the antenna demonstrates impressive impedance bandwidths of 5.6 %, 5.2 %, and 6.5 % at a nearly common frequency of 2.7 GHz, coupled with respectable gains of 8.12dBi for LP, 11.19dBic for LHCP, and 10.55dBic for RHCP configurations, respectively. The comprehensive design details, along with extensive experimental and simulated findings, are meticulously presented, underscoring the antenna’s remarkable performance and potential for diverse wireless communication scenarios.