A systematic and novel design process for tailored bandwidth filtering power divider (TBFPD) has been developed, leveraging the off-resonance behavior of LC-resonators to achieve compact bandpass filtering characteristics in an artificial transmission line (ATL). In this approach, the ATL's passband is realized at a frequency higher than the LC-resonator's natural resonance, enabling significant bandwidth (BW) tuning. Additionally, a new circuit modeling approach has been introduced, enabling precise control over filtering response and impedance transformation, making it a valuable tool for designing highly adaptable RF power dividers. In comparison with recently reported power dividers, it offers comparable compactness, stop band rejection, flat group delay with a wider passband BW, making it a promising candidate for wireless communication systems. The proposed FPD-based combining topology enhances spectral purity, leading to improved dynamic range and reduced false target detection, showing its capability for radar systems.

This work reports three designs of transverse resonance (TR)-based high-performance compact 5-pole Butterworth low-pass filters (TR-LPFs) at the cut-off frequency ( fc ) 10.5 GHz in 0.15 μm Gallium Arsenide (GaAs) pHEMT technology, with a chip size of 0.82 mm × 0.87 mm. Two fabricated TR-LPFs have 20 dB, 30 dB, 40 dB, and 50 dB attenuation levels with rejection bandwidths of (54 GHz, 54 GHz), (32 GHz, 52 GHz), (31 GHz, 50 GHz), and (18.5 GHz, 27 GHz) respectively, and insertion loss of 0.5 dB and 0.6 dB. The TR-LPF is a microstrip-based design, so unlike the lumped elements-based design, it could be designed and fabricated in the GaAs, and other technologies even at millimeter-wave frequencies. Such high performance LPF, using microstrip on a GaAs chip is not reported in the open literature.

Normally, the reported gain of the microstrip patch antenna is within 8 dBi. Using properly located three shorting pins on three bisectors, the present work reports a method to convert the non-radiating TM11 mode of equilateral triangular patch antennas (ETPAs) to a deformed TM11 radiating mode. The boresight gain of ETPA operating in TM11 mode is enhanced from -10.75 to 12.1 dBi at 5.43 GHz. The boresight measured gain is further enhanced to 14.2 dBi at 5.52 GHz by using a triangular surface-mounted short horn (SMSH) of about ${{\lambda }}/5$ height. The aperture efficiency of the ETPA with the shorting pins is 84.2%. The aperture efficiency is further improved to 94.2% using the SMSH. The measured boresight cross-polarization and side-lobe level are -40 and -29 dB, respectively. The nature of the electricfield and surface current distribution is analyzed, using both the characteristic mode analysis method and high-frequency structure simulator, to understand the role of shorting pin and coaxial feed in converting the non-radiating TM11 mode to the radiating mode. A systematic design process also is presented for a fast design of shorting pin-loaded ETPA on the suitable substrate at a specified frequency.

In this work, a systematic design method for a compact 5-pole Butterworth transverse resonance low pass filter (TR-LPF), in 0.15 mu m Gallium Arsenide process, with wide rejection bandwidth (RBW), is presented. The circuit model of TR-LPF and closed-form expressions are provided to appreciate the design process. The fabricated TRLPF has a cut-off frequency of 10.5 GHz, an insertion loss of 0.4 dB, and the return loss is better than 20 dB. The 20 dB, 30 dB, and 40 dB deep rejection bandwidths (RBWs), across 50 GHz, 45.5 GHz, and 17 GHz respectively, are obtained. The novel use of stubs and spur resonators, within stubs; provides the deep and wide RBW. The compactness of the TR-LPF is realized by the 'C ' -and 'Z '-shaped folding of stubs. The dimension of the filter is approximately 0 .11 lambda g x 0 .079 lambda g .

This chapter provides a very brief historical overview of the classical and modern planar transmission lines. It reviews the classical transmission lines such as a single‐wire line with the earth as a return conductor, coaxial cable, two‐wire line, multi‐conductor lines, and waveguides. The chapter emphasizes the developments of basic concepts, analytical modeling, and theoretical formulations used in the electromagnetic‐theory. The development of the theoretical models of transmission lines inherited the modeling process, and mathematical method of Fourier developed for the transmission of heat in a rod. On knowing the magnetic effect created by an electric current, Faraday argued that the magnetic field can also produce the electric effect. The chapter presents a brief review of the development of planar transmission lines, influencing modern microwave technology. The waveguide is a low‐loss transmission medium capable of handling high power transmission. The chapter also presents an overview on the key concepts discussed in this book.

This paper presents the 3D prism-shaped circularly polarised MIMO Diversity Antenna with 360° angular coverage. The proposed antenna has six elements, and it covers the X-band with impedance matching from 8.0 to 11.8 GHz (38.4%), 3 dB axial ratio from 8.05 to 10.6 GHz (27.34%). A metallic copper cylinder is placed inside the prism to improve the isolation and axial ratio. All the antennas are highly isolated, with isolation is more diminutive than −20.5 dB, except the adjacent element to the edge of the prism, for which it is −14.7 dB. The Envelope Correlation Coefficient (ECC) is less than 0.035. The proposed antenna structure shows the pattern or angle diversity in the whole 360° angle with polarisation diversity.

The present work describes a new wideband circularly polarized MIMO rectangular antenna in cube form for X-band application (8 to 11.8 GHz). The proposed antenna structure shows pattern diversity in whole 360◦ angle with polarization diversity. The isolation between the antennas is more than −14.5 dB. The impedance matching bandwidth (IMBW) is 3.8 GHz, and 3 dB axial ratio bandwidth is 2.91 GHz. The envelope correlation coefficient is less than 0.035, and its diversity gain is 10 dB. A copper metallic cylinder is placed inside the cube antenna to reduce the mutual coupling between the antennas.

In this article, the propagation characteristic of transient pulses over the designed microstrip THz interconnects by various conducting materials is analyzed. The Fourier inverse transformation approach is used to visualize the effect of propagation of transient pulses over THz interconnects made by the various conducting materials which are widely used in Complementary Metal Oxide Semiconductor (CMOS) technology named Copper, Gold, Aluminum, Tungsten, Tungsten-Silicide (W-Si2) and Poly-Si respectively. All parameters of transient pulse like rising time, fall time, propagation delay, settling time, overshoot, undershoot and ringing, etc. have calculated using the proposed circuit model and it has been verified with Finite Elements Method based EM-Simulation results. The distortion due to geometrical dispersion is significant; while a loss could be an important factor depending on the dielectric loss of the substrate. This information could be useful in designing both on board and on-chip interconnects. The proposed circuit model of microstrip THz interconnects and algorithmic frameworks proved the usefulness of rapid design, which is extremely challenging when using conventional methods. To the awareness, this is the attempt to efficient solving of this type of design problems; especially in the context of explicit THz interconnect design for CMOS technology.

A computer-aided design modeling is presented to compute a shunt capacitance and series inductance of π or T-equivalent network parameters of microstrip step-discontinuity at a junction on multilayer iso/anisotropic substrates. The results of the proposed model of shunt capacitance and series inductance have shown permissible agreement with simulation results by the average deviation of 4.5% and 4.9% for 1 < ε r ≤ 40 and w 1 /w 2 < 10 respectively. Similarly, the transient signal propagation characteristics, such as arrival time of the pulse, rise-time, delay time, settling time, etc. are influenced by the anisotropy in the transmission line and said information’s are also important for proper characterization of analog/digital pulses on multilayer iso/anisotropic substrate planar transmission lines. The time-domain characteristic of transient pulses over microstrip stepped line with diverse conditions are strengthening the concept of interconnects, which plays a vital role in modern circuit technology. Proposed modeling concept is more accurate to design of contemporary planar microwave filters, impedance matching networks and VLSI interconnects.

Spintronic devices are considered as promising candidates in implementing neuromorphic systems or hardware neural networks, which are expected to perform better than other existing computing systems for certain data classification and regression tasks. In this paper, we simulate with micromagnetic framework a spin orbit torque driven domain wall based synaptic device, based on existing theoretical and experimental studies of current driven domain wall motion in heavy metal/ferromagnet heterostructures. Next we design a feedforward Fully Connected Neural Network (FCNN) with no hidden layer using several such domain wall devices as synapses and transistor based analog circuits, which we also simulate using analog circuit simulator, as neurons. An analog peripheral feedback circuit is also designed using transistors, which at every iteration computes the change in weights of the synapses needed to train the network using Stochastic Gradient Descent (SGD) method. Subsequently it sends write current pulses to the domain wall based synaptic devices which move the domain walls and update the weights of the synapses. Next we demonstrate through simulating "on-chip" learning of the designed FCNN on the MNIST database of handwritten digits that our FCNN trains itself in hardware through continuous update of the weights in the synapses. Previous simulation reports of spintronic FCNN do not show such peripheral circuits needed for "on-chip" learning and hence only show "off-chip" learning, where the final weights of the network are first calculated in a separate computer and then directly stored in the synapses. We obtain fairly high training and test accuracy for "on-chip" learning of our network. We also report energy dissipated in the synaptic devices for the training in this paper.

In this study, the authors propose a new type of metasurface, namely a sandwiched anisotropic metasurface, for converting a linearly polarised elliptical patch antenna into a wideband circularly polarised antenna. A partially reflecting surface (PRS) as a superstrate is further used to enhance the gain of the antenna. The design rules of the antenna are also presented. The combined metasurface and the PRS-based patch antenna is designed on a low-cost substrate FR-4. The realised 3 dB axial ratio bandwidth (ARBW) of the antenna is 1.01 GHz (3.55–4.56 GHz), its impedance matching bandwidth is 1.33 GHz (3.08–4.41 GHz), and its peak gain varies from 7 to 7.84 dB within the band. By placing the PRS superstrate above the antenna, gain further improves to 9.32 dBi without degrading the performance of the antenna. Measured results are presented to validate the antenna performance and results are compared against a large number of similarly available antenna.

In this study, presented a computer-aided design-based circuit model which is applicable to microstrip transmission line for terahertz interconnects technology in circuit simulator. Comparison of modified Kirschning and Jansen for dispersion and modified characteristic impedance for characteristic impedance models with full-wave electromagnetic (EM) simulator are investigated which shows < 1% devi...

In this paper, presented a computer aided-design (CAD) based circuit model which is applicable to microstrip transmission line for THz interconnects technology in circuit simulator. Comparison of MKJ for dispersion and MCI for characteristic impedance models with full-wave EM simulator are investigated which shows <1% deviation for w/h range 0.1 <= w/h <= 100, conductor thickness 0.001 <= t/h <= 0.2, wavelength range 8.7um <=lambda g <= 8.7m and substrate permittivity 1.0 <= epsilon(r) <= 200. MCL for conductor loss and MDL for dielectric loss are also investigated and compared with EM simulator, which shows deviation of <1dB for above said electrical and physical set of range of parameters. Calculation of line parameters: (f, t), (f, alpha), R(f), L(f), C(f), G(f) by using the effect of dispersion, characteristic impedance and losses which shows <1% deviation with experimental data available. Accuracy of the circuit model are also verified for interconnects made by aluminum (sigma(o)=3.7x10(7) S/m), tungsten (sigma(o) = 1.0x10(7) S/m) and tungsten-silicide (sigma(o) = 3.3x10(6) S/m) conductors which used in VLSI/ULSI Technology.

This paper presents a design of a multiband MIMO microstrip patch antenna. The isolation between the two ports varies from 12.5 dB to 44 dB for all the available bands. Proposed antenna is useful for C-Band, X-Band, K-Band and Ku-Band applications. The proposed antenna shows the circular polarization behavior at 5.27 GHz (5.26 GHz–5.31 GHz), 6.20 GHz (6.18 GHz–6.22 GHz), 11.89 GHz (11.72 GHz–12.24 GHz), 13.56 GHz (13.46 GHz–13.61 GHz), 16.68 GHz (16.55 GHz–16.85 GHz), 21.17 GHz (21.17 GHz–21.20 GHz) and 22.84 GHz (22.28 GHz–22.93 GHz). The proposed antenna is designed on FR-4 substrate with relative permittivity 4.4 and thickness 1.59 mm.

This paper addresses an accurate CAD oriented integrated closed-form model for the computation of losses for planar and non-planar slotline on a finite-thickness multilayered dielectric substrates. The analysis of the structures has been done using conformal mapping and single layer reduction (SLR) technique. The validity of the proposed integrated model is tested over wide range of parameters: 1 GHz ≤ f ≤ 60 GHz, 0 μm ≤ t ≤ 50 μm, 2.2 ≤ ε r ≤ 20 and 0.02 ≤ w/h ≤ 1.0 against the 3D-EM simulated results. The average deviation of the model against the comparison is 3.4%.

In this paper, we present the closed-form models of conductor thickness dependent dispersive line parameters and losses, of multilayer coplanar stripline (CPS) on isotropic dielectric substrates. The dispersive empirical expressions for the single-layer CPS from literature are improved to include the finite conductivity and finite conductor thickness in propagation characteristics and losses. The single layer reduction (SLR) formulation of lossy multilayer CPS is then used to extend the closed-form models developed for computation of line parameters, to multilayer structures. All developed models are verified against the results obtained using the EM-simulators for frequency range 1 GHz 60 GHz over wide range of parameters.

New kind of the microstrip 5 to 11 - pole lowpass filters, called the Linear-Butterworth Transverse Resonance LPF (LB-TR-LPF), with high selectivity in the range of 40 dB/GHz - 80 dB/GHz and wide rejection bandwidth is presented. These filters have maximally flat passband response governed by the Butterworth prototype LPF; while their stopband characteristics - the high selectivity and the large rejection BW, are governed by the linearly distributed multiple transmission zeros.

This paper presents a design of compact a triple-band bandstop filter (BSF) using embedded chip capacitors. The presented BSF is useful to suppressing the signal frequencies 2.2 GHz, 5.53 GHz and 4.15 GHz from the WLAN and UWB band with attenuation level 33.5 dB, 27.6 dB and 24.9 dB, respectively. The quality factors of the three bands are 5.21, 31.92 and 79.0, respectively. The simulated and measured results are presented to validate the concept. Such BSFs could find application in modern communication systems to suppress the potential interference of the unwanted frequencies from the WLAN and UWB band.