Microelectronics International

S., Karthie; J., Zuvairiya Parveen; D., Yogeshwari; E., Venkadeshwari

2022 Microelectronics International

doi: 10.1108/mi-08-2021-0080

The purpose of this paper is to present the design of a compact microstrip bandpass filter (BPF) in dual-mode configuration loaded with cross-loop and square ring slots on a square patch resonator for C-band applications.Design/methodology/approachIn the proposed design, the dual-mode response for the filter is realized with two transmission zeros (TZs) by the insertion of a perturbation element at the diagonal corner of the square patch resonator with orthogonal feed lines. Such TZs at the edges of the passband result in better selectivity for the proposed BPF. Moreover, the cross-loop and square ring slots are etched on a square patch resonator to obtain a miniaturized BPF.FindingsThe proposed dual-mode microstrip filter fabricated in RT/duroid 6010 substrate using PCB technology has a measured minimum insertion loss of 1.8 dB and return loss better than 24.5 dB with a fractional bandwidth (FBW) of 6.9%. A compact size of 7.35 × 7.35 mm2 is achieved for the slotted patch resonator-based dual-mode BPF at the center frequency of 4.76 GHz. As compared with the conventional square patch resonator, a size reduction of 61% is achieved with the proposed slotted design. The feasibility of the filter design is confirmed by the good agreement between the measured and simulated responses. The performance of the proposed filter structure is compared with other dual-mode filter works.Originality/valueIn the proposed work, a compact dual-mode BPF is reported with slotted structures. The conventional square patch resonator is deployed with cross-loop and square ring slots to design a dual-mode filter with a square perturbation element at its diagonal corner. The proposed filter exhibits compact size and favorable performance compared to other dual-mode filter works reported in literature. The aforementioned design of the dual-mode BPF at 4.76 GHz is suitable for applications in the lower part of the C-band.

Sahoo, Ratikanta

2022 Microelectronics International

doi: 10.1108/mi-11-2021-0115

This paper aims to propose a cylindrical conformal wideband antenna with increased directive behaviour using integrated parasitic triangular-shaped elements for WiMAX application.Design/methodology/approachThe proposed antenna is a wideband directional cylindrical conformal antenna consisting of three fork-shaped dipole elements incorporated with parasitic triangular-shaped reflecting components increases the gain of reference conformal antenna. The novel parasitic elements with triangular shapes are designed on the radiating patch as well as the ground plane side. The parasitic triangular elements enable the antenna to enhance the gain along the end-fire direction.FindingsThe proposed antenna has a 20.2% impedance bandwidth ranging from 3.1 to 3.8 GHz. The half power beam-width (HPBW) of the reference antenna in the H-plane is 122.9° and falls to 99.1° after integrating with parasitic elements at 3.3 GHz, whereas it falls from 56.7° to 54.7° in the E-plane. However, at 3.5 GHz, the reference antenna’s HPBW is at 116.8°, which decreases to 92.4° in the H-plane, whereas it reduces from 57.9 to 53.4° in the E-plane. The proposed antenna has a lower HPBW than reference antennas and achieved a gain enhancement of 1.2 dBi, indicating that the pattern becomes more directed.Originality/valueIn the proposed work, the directive behaviour of cylindrical conformal antenna structure with a 30 mm radius of curvature is improved using parasitic reflective elements. The fabricated antennas’ experimental findings are an excellent contender for wireless point-to-point WiMAX applications because it features a wideband, directional properties, and strong gain over the whole operational frequency range of 3.1–3.8 GHz.

Pandey, Jai Gopal; Gupta, Sanskriti; Karmakar, Abhijit

2022 Microelectronics International

doi: 10.1108/mi-09-2021-0091

The paper aims to develop a systematic approach to design, integrate, and implement a set of crypto cores in a system-on-chip SoC) environment for data security applications. The advanced encryption standard (AES) and PRESENT block ciphers are deployed together, leading to a common crypto chip for performing encryption and decryption operations.Design/methodology/approachAn integrated very large-scale integration (VLSI) architecture and its implementation for the AES and PRESENT ciphers is proposed. As per the choice, the architecture performs encryption or decryption operations for the selected cipher. Experimental results of the field-programmable gate array (FPGA) and application-specific integrated circuit (ASIC) implementations and related design analysis are provided.FindingsFPGA implementation of the architecture on Xilinx xc5vfx70t-1-ff1136 device consumes 19% slices, whereas the ASIC design is implemented in 180 nm complementary metal-oxide semiconductor ASIC technology that takes 1.0746 mm2 of standard cell area and consumes 14.26 mW of power at 50 MHz clock frequency. A secure audio application using the designed architecture on an open source SoC environment is also provided. A test methodology for validation of the designed chip using an FPGA-based platform and tools is discussed.Originality/valueThe proposed architecture is compared with a set of existing hardware architectures for analyzing various design metrics such as latency, area, maximum operating frequency, power, and throughput.

Mohamed Sunar, Mohamad Solehin; Abu Bakar, Maria; Jalar, Azman; Ramli, Mohamad Riduwan; Che Ani, Fakhrozi

2022 Microelectronics International

doi: 10.1108/mi-12-2021-0121

Reflow solder joint quality is significantly affected by the ability of the solder to perfectly fill pad space and retain good solder joint shape. This study aims to investigate solder joint quality by quantitatively analyzing the stencil printing-deposited solder volume, solder height and solder coverage area.Design/methodology/approachThe dispensability of different solder paste types on printed circuit board (PCB) pads using different stencil aperture shapes was evaluated. Lead-free Type 4 (20–38 µm particle size) and Type 5 (15–25 µm particle size) solder pastes were used to create solder joints according to standard reflow soldering.FindingsThe results show that the stencil aperture shape greatly affects the solder joint quality as compared with the type of solder paste. These investigations allow the development of new strategies for solving solder paste stencil printing issues and evaluating the quality of solder joints.Originality/valueThe reflow soldering process requires the appropriate selection of the stencil aperture shape according to the PCB and the solder paste according to the particle-size distribution of the solder alloy powder. However, there are scarce studies on the effects of stencil aperture shape and the solder alloy particle size on the solder paste space-filling ability.

P., Ponnammal; J., Manjula

2022 Microelectronics International

doi: 10.1108/mi-12-2021-0119

This paper is aimed to study the design of a miniaturized filter with tri-band characteristics. In this paper, perturbation is used to realize circuit miniaturization and multi-band by exploiting the inductive property. During this process, vias are added for twofold benefit, namely, circuit miniaturization and enhanced frequency selectivity at high frequency. Thus, with the introduction of the shorting via, the single-band dual-mode bandpass filter is converted into a tri-band filter with a smaller electrical size.Design/methodology/approachThis paper presents the design and characterization of a miniaturized two-port filter with tri-band operating characteristics. The proposed filter is constructed using a square patch resonator operating at 5.2 GHz with a capacitively coupled feed configuration. A square perturbation is added to the corner of the square patch to achieve diagonal symmetry and to excite dual mode. The perturbation offers a sharp transmission zero defining bandwidth of the proposed filter. In addition, a shorting post is introduced to achieve an 88% size reduction by lowering the operating frequency to 1.8 GHz.FindingsThe prototype filter has insertion less than 1.2 dB and return loss better than 12 dB throughout all the realized frequency bands. The prototype filter is fabricated and the simulation results are validated using experimental measurements. The realized fractional bandwidths of the proposed bandpass filter are 11/5.6/1 at 1.8/4.6/5.85 GHz, respectively. The quality factor of the proposed antenna is greater than 80 and a peak Q-factor of 387 is realized at 5.85 GHz. The high Q-factor indicates low loss and improved selectivity. The rejection levels in the stopband are greater than 20 dB.Originality/valueThe results indicate that the proposed filter is a suitable choice for low-power small-scale wireless systems operating in the microwave bands. The realized filter has the smallest footprint of 0.36λeff  × 0.19λeff where λeff is the effective wavelength calculated at the lowest frequency of operation.