Transmission Line Unit Cell Research Articles

Design and analysis of SRR based metamaterial loaded circular patch multiband antenna for satellite applications

Satellite communication has reached a turning point in transmitting data quickly and receiving signals clearly in faraway places. This paper presents a metamaterial-based antenna for distant and military applications that overcomes restrictions and performs unmatched. This project explores metamaterials to create a unique antenna. Expect to be astounded by its power to bend electromagnetic waves, miniaturize, and change our relationship with the universe. The feeding mechanism of this antenna is a modified co-planar waveguide. At 5.6 GHz, the proposed antenna unit cell measures 0.076λ0×0.2λ0, making it small thanks to its MTM characteristic. CP radiation is made when two orthogonally polarized modes are stimulated at the same time and two composite right- and left-handed transmission line unit cells are placed orthogonally. Reduced size, increased bandwidth, and improved Learn how this discovery opens new doors for high-resolution photography, broadband internet, and space exploration. One nanostructure that makes up a metamaterial is the Split Ring Resonator (SRR). SRR dimensions must be smaller than the resonance wavelength, making them crucial for near-infrared and optical responses. This effort examined nanoscale SRR characteristics in the infrared and visible ranges. SRRs composed of aluminum (Al) and gold (Au) were produced on silicon and silica substrates using electron beam lithography (EBL). The proposed structure consists of a microstrip-line-supplied SRR, a parasitic patch that is perpendicular to the ground plane, and two via holes connected by two split rings that feed the patch indirectly. Choosing the right material parameter for all such antennas depends on the planned structure. Fabrication and testing of the antenna matched simulations. Dimensions: 23.7 mm × 16.2 mm × 1.6 mm; substrate dielectric constant: 4.4. Experimental data are detailed and compared to analytical calculations. Simulation results show that metamaterials have negative permittivity and permeability in a certain frequency range, which can be predicted by an analytical method. Simulations indicated eight BRS, WiMAX, radar, and mobile phone resonance frequencies. Radiation is dipole-like in the omnidirectional in the H-plane and E-plane. 10 dB return loss and 3 dB axial ratio bandwidths are 38.6.7% and 8.1%, respectively.

The development of a 10.7-MHz fully balanced current-tunable bandpass filter with Caprio technique

Bandpass filters are integral in modern communication systems for selecting specific frequency ranges to ensure interference-free signal transmission and reception. This paper explores various bandpass filter designs, including those using active inductors, transmission-line unit-cells, microstrip open-loop resonators, and dual-port dual-frequency integration antennas. The focus is on the 10.7-MHz bandpass filter, widely used in FM radio and television systems. The study evaluates current-controlled and balanced designs, analyzing their performance, advantages, and drawbacks. Unique trade-offs in terms of linearity, distortion, temperature sensitivity, and component variations are discussed. Additionally, advancements in filter technology and diverse design options are presented. The paper introduces a novel current-balanced, frequency-adjusted bandpass filter to address odd-order noise issues. This filter aims to achieve high linearity, harmonic distortion attenuation, and the elimination of even-order harmonics. Through synthesis, analysis, simulation, and comparison with traditional filters, the proposed design enhances signal quality and efficiency. The fully-balanced current-tunable bandpass filter with the Caprio technique at 10.7 MHz is developed, exhibiting symmetrical characteristics with lower total harmonic distortion. The circuit’s structure is simple and adaptable for integration, validated through consistent simulation results. The study concludes by emphasizing the constant sensitivity of transistor differential amplifier circuits to the center frequency and the linear relationship between center frequency and adjustable bias current. The suggested transistor and capacitor selection criteria contribute to optimizing the circuit’s performance, aligning with the Caprio technique’s recommendations. Overall, this research presents a promising solution for achieving high-quality signal transmission in contemporary communication systems

A VHF Band Small CRLH Antenna Using Double-Sided Meander Lines

In this paper, a miniaturized very-high frequency (VHF) band antenna using both top and bottom meander lines is proposed. To design a compact size antenna in the VHF band, a Composite Right/Left-Handed (CRLH) transmission line is applied to antenna structure; additionally, both top and bottom meander lines were used to achieve a greater inductance. The CRLH transmission line unit cell operates at 88 MHz, and the fabricated antenna is designed by arranging 7-unit cells. The overall size of the proposed antenna is 0.087λ × 0.02λ × 0.0003λ at the lowest operating frequency, and the antenna operates at 84 MHz. The VSWR 3.5:1 reference operating bandwidth of the antenna is 2%. The received power of the proposed CRLH antenna was measured to verify the antenna performance.

Wideband asymmetric coplanar waveguide antenna using composite right/left‐handed transmission line

AbstractA broadband asymmetric coplanar waveguide antenna is designed. In this design, two periodical composite right/left‐handed transmission line (CRLH‐TL) unit cells were chosen to generate three resonating modes. The broadband characteristic of this antenna can be achieved by combining the first‐negative‐order resonance, zeroth‐order resonance, and first‐positive‐order resonance of CRLH‐TL. A prototype structure of our proposed antenna has been fabricated and tested. The dimensions of the antenna are 30.0 × 40.0 × 1.6 mm3, which corresponds to 0.19 × 0.25 × 0.01 , where is the free‐space wavelength at 1.88 GHz. The measured band in which S11 is below −10 dB ranges from 1.80 to 3.75 GHz with the fractional bandwidth of 70.27%. The radiation patterns of the proposed antenna are highly consistent throughout the operating band, which covers the band of WiMAX, with the measured average peak gain of 2.77 dBi and radiation efficiency of 86.63%.

A Broadband Antenna Based on a Single CRLH TL Unit Cell and a Parasitic Strip for Sub-1GHz DVB and LTE Applications

A Broadband and slim profile antenna based-on a single composite right/left-handed transmission line unit cell and parasitic shorted strip is presented for sub-1 GHz digital video broadcasting and long-term evolution applications (470-970 MHz). It is comprised of an ungrounded coplanar waveguide that feeds a meandered strip (distributed series inductors), which is connected through capacitive coupling (series capacitance) with a virtual small ground, while an upper shorted meandered strip represents a parallel inductor. A shorted meandered strip (parasitic inductor) is added to create a third resonant frequency. A broadband operation is achieved by merging three different resonant modes frequencies (zeroth-order mode and two quarter wavelength monopole modes) to satisfy 6 dB bandwidth criterion. A prototype is constructed and measured in order to verify the achieved results. The results of reflection parameter, gain, efficiency, patterns and bandwidth efficiency product are presented, discussed, and evaluated with respect to literature. The results show that the proposed antenna is a potential candidate for recent broadband digital video broadcasting applications.

A dual-band, dual-polarized, CPW-fed wideband antenna loaded with via less CRLH-MTM TL for 5G mm-Wave communication

This paper effectively implements the process of bandwidth enhancement and realization of circular polarization (CP) of metamaterial-based antenna by loading composite right/left-handed (CRLH) transmission line (TL) unit cell without vias. This antenna is a symmetrical structure that comprises of square slot, two asymmetric meander lines (AML) in y-direction, an interdigital capacitance (IDC) in x-direction, inductive rhombus (IR), and coplanar waveguide (CPW) feed line in a single plane. Mender lines (ML) provides the needed shunt inductance whereas IDC in the signal line provides series capacitance for left-handed TL. The proposed metamaterial-based antenna structure essentially produces three resonating bands. The simulated first band has a frequency range of 14.5 GHz to 15.4 GHz due to zeroth-order resonance (ZOR), which can be used for satellite communication. Dispersion analysis is done to verify metamaterial (MTM) behavior at ZOR frequency using Bloch-Floquet theory. The second and third resonance are due to coupling capacitances, created in antenna structure, which are merged to make a broadband antenna in millimeter-Wave (mm-Wave) range from 28 GHz to 39.2 GHz, for 5G cellular communication by increasing the diagonal length of IR. The CP is attained by converting symmetric meander lines (MLs) to asymmetric MLs to excite the orthogonal field components of equal amplitude. The simulated results are compared to measured results and found to be in a good match. The measured impedance bandwidth (IBW) for the Ku-band is 7.31% (14.5–15.6) GHz with linear polarization (LP) characteristics while 31% (28–38.2) GHz in mm-Wave (Ka-band) range. The measured axial ratio bandwidth (ARBW) is 5.2 GHz (13.9%, 33.6 GHz-38.8 GHz) in mm-Wave range. The proposed antenna has a peak gain of 6.7 dBi and maximum efficiency is 93%. The overall dimension of the presented antenna is 0.5λ0 × 0.5λ0 × 0.025λ0 at 14.9 GHz.

A compact dual-band D-CRLH-based antenna with self-isolation functionality

AbstractThis paper presents a compact dual-band filtering antenna without extra employing of filter structures. The antenna is designed using a planar dual-composite right/left-handed (D-CRLH) transmission line unit cell, where the filtering function is achieved through current cancellation between the D-CRLH resonators. The antenna is designed to function at 3.0 and 5.1 GHz, which can serve different WLAN applications. The antenna is a co-planar waveguide fed with a very compact size of only 30 × 16 mm2. Compared to the conventional patch antenna, the antenna size is only 17% at 3.0 GHz and 31% at 5.1 GHz. Despite the small size, the antenna preserves a good omni-directional radiation pattern at the two resonant frequencies with a measured realized gain of 2 and 2.7 dB, respectively. At the stopband in-between the two resonant bands, the reflection coefficient is almost 0 dB at 4.25 GHz and complete non-radiation is proved with a −11 dB measured realized gain. The different antenna filtering functions are verified by full-wave simulation and measurements.

Terahertz Quasi-TEM Mode Tunable Composite Right/Left-Handed Leaky-Wave Antennas Using Graphene-Based Coplanar Waveguides

A novel and simple scheme for the realization of the terahertz (THz) fundamental-mode composite right/left-handed leaky-wave antennas (CRLH LWAs) is proposed. The CRLH LWAs are reconstructed by graphene-based coplanar waveguide transmission line (CPW TL) unit cells. Their signal lines are grounded by narrow graphene strips to achieve the shunt inductances, and parallel-plates are periodically added along the signal line to obtain the series capacitances. The propagation properties of the LWAs are detailed. The LWAs have both left-handed (LH) and right-handed (RH) regions by varying frequency. By numerical simulations, the LWAs are verified. Their backfire-to-endfire beam-steering capabilities through frequency scanning are confirmed. Compared with the CRLH LWAs at THz proposed in previous literature, the graphene-based CRLH LWAs operate in the Quasi-TEM mode. They possess low fabrication, excitation, and impedance matching difficulty. They also show the possibility of integration with other micro-devices. With the application of graphene, the LWAs exhibit strong tunable characteristics that conventional CRLH LWAs are absent. Therefore, the proposed CRLH LWAs have great potential applications for the development of beam-steering antennas at THz.

Ultra-Wideband Metamaterial-Loaded Microstrip Array Antennas using Fibonacci & Fractal Geometric Patterns, Design and Modelling

In this study; theory, design and modeling of a new topology of ultra-wideband (UWB) metamaterial (MTM) loaded microstrip array antenna using Fibonacci & fractal geometric patterns are analyzed. This antenna is made basically from many monopole elements which are loaded by complementary metamaterial transmission line (CMTL) unit cells. The distributed CMTL element, contains a Koch-shaped expanded complementary single split ring resonator (CSRR) pair. At first step, the UWB microstrip array antenna designed with two CMTL-loaded monopole element. So, using an iterative method based on the Fibonacci and fractal geometry patterns, the array antenna is expanded. As the order of iteration increases, the impedance bandwidth of the proposed array antennas improve more, and the radar cross section (RCS) decreases. the impedance bandwidth of the proposed third-order Fibonacci and fractal CMTL-loaded array antennas are 250 MHz and 539 MHz more than the two-element CMTL-loaded array antenna, respectively. Finally, this paper presents an improved method to extract the parameters of an equivalent circuit model of the proposed MTM-loaded array antenna. Verification of the equivalent model have been validated utilizing ADS software. The obtained model, in addition to numerically efficient in comparison with the full wave analysis utilizing the moment method, gives a good physical insight to the mutual coupling mechanism of the array antenna.

Coaxial‐fed high‐gain triple‐band zeroth‐order circularly polarized antenna using pseudo‐open termination and asymmetric unit cells

A coaxial-fed tri-band zeroth-order resonance (ZOR) circularly polarized antenna with higher gains for all the excited ZORs is designed and analyzed in this paper. Epsilon negative transmission line (ENG TL) and pseudo-open termination (P-OT) unit cells with different series capacitances (CS and CS1) resonate shunt ZOR (fsh) and two series ZORs (fse and fse1), respectively. Asymmetric unit cell concept is applied to ENG-TL and P-OT unit cells to create vertical and horizontal components, and the 90° phase shift is provided by the ZOR, resulting in circular polarization (CP). Left-hand CP (LHCP) is achieved by creating two 90° right bends to the extended stubs in ENG TL and P-OT unit cells. Higher gains for all the excited ZORs are achieved by shifting the shorting pins of ENG TL and P-OT unit cells far away from the center position. After fabrication, the measured resonances occur at 4.64 GHz (fsh), 4.04 GHz (fse), and 3.86 GHz (fse1) with fractional bandwidths of 1.62%, 1.73%, and 1.6%, respectively. The measured LHCP peak gains are 4.05 dBic (fsh), 3.85 dBic (fse), and 3.94 dBic (fse1). The average axial ratio obtained is less than 3-dB in the 10-dB fractional bandwidth of the proposed antenna.

Wideband Dual Circularly Polarized Antenna for Intelligent Transport Systems

A wideband dual circularly polarized (DCP) antenna is presented for intelligent transport system (ITS) applications, which can be used to improve the receiver sensitivity and communication quality of ITS. The presented DCP antenna is composed of an orthogonal power divider (OPD) with two orthogonal input ports, four phase shifters for quadrature phase output, and four crossed dipoles for DCP radiation. Detailed equivalent circuit analysis shows that the OPD has two orthogonal inputs and four equal magnitude in-phase and out-of-phase outputs. To achieve two sets of orthogonal quadrature output signals for DCP radiation, the lumped element based differential right-hand transmission line unit cell and left-hand transmission line unit cell are elaborately introduced as the ±45° phase shifters, and incorporated into the OPD. Eventually, orthogonal quadrature signals are successfully obtained and fed to the crossed dipoles for DCP radiation. The proposed antenna was then designed, fabricated, and measured for ITS applications. The measured results show that the overlapped impedance bandwidth of both two input ports is 1.07–1.85 GHz (53.4%), and the isolation is higher than 15.2 dB. Moreover, low axial ratio (<1.7 dB) and symmetrical radiation patterns are achieved for unidirectional DCP radiation.

UWB bandpass filter with compact size and wide upper stopband

AbstractA novel ultra‐wideband (UWB) bandpass filter (BPF) with a very compact size and improved out‐of‐band performance is proposed in this letter. The main circuit structure is a composite right‐/left‐handed transmission line unit cell, which has UWB bandpass characteristic as well as compact size. Moreover, two anticoupled line structures added at both ends of the unit cell can produce a new resonant mode and three transmission zeros, so the passband response and upper stopband performance can be improved. The proposed filter is implemented and measured, which shows its 3 dB passband ranges from 3.3 to 10.9 GHz with a fractional bandwidth of 110.9%. Its insertion loss is about 0.6 dB at the centre frequency, while the return loss is better than 13 dB. In addition, the measured results also show the proposed filter has a wide stopband from 11.4 to 30 GHz, whose rejection level is greater than 18 dB. The size of the filter is only 7.4 × 6.4 mm, equal to 0.22 × 0.20 λg. Both the simulated and measured results are in good agreement.

Compact ultra-wideband bandpass filter based on composite right/left-handed transmission line with improved out-of-band performance

ABSTRACTThis paper presents a novel compact ultra-wideband (UWB) bandpass filter (BPF). It consists of two composite right/left-handed transmission line (CRLH-TL) unit cells and an anti-coupled line structure. The CRLH-TL unit exhibits good passband performance with a compact size. By cascading the anti-coupled line structure, a wide upper stopband is obtained. The measured fractional bandwidth and insertion loss are 113.9% and 0.52 dB, respectively. Moreover, a broad stopband from 14 to 30 GHz with a high rejection level of 20 dB is obtained. The whole size is 14.4 mm × 10.2 mm. The simulated and measured results agree well.

Metamaterial‐based wideband circularly polarised antenna with rotated V‐shaped metasurface for small satellite applications

This Letter explains the design and development of a wideband circularly polarised (CP) antenna based on composite metamaterial (MTM) structures which are applicable for use in small satellite applications. The presented antenna is based on a modified co-planar waveguide feeding technique. The proposed antenna unit cell offers compact size due to its MTM property with dimensions of 0.088λ 0 × 0.19λ 0 at 2.4 GHz. The CP radiation is obtained by placing two composite right/left-handed transmission line unit cells orthogonally and exciting two orthogonally-polarised modes simultaneously. A new 4 × 4 unit cell artificial magnetic conductor metasurface is designed with a compact size at the same operating frequency of MTM-based CP antenna as a ground plane for the proposed antenna, which is found to be increased bandwidth, improved gain, and wider axial ratio bandwidth without altering the antenna compactness. The final antenna obtains an overall dimension of 0.37λ 0 × 0.37λ 0 × 0.18λ 0 at 2.5 GHz. The measured result shows a wider impedance bandwidth of 860 MHz (33.07%), improved axial ratio bandwidth of 410 MHz (15.92%), and a good gain of 5.76 dBic is obtained which are adequate for the use in modern small satellite applications.

A compact ultra wide band bandpass filter with dual band notch designed based on composite right/left‐handed transmission line unit cell

In this article, we propose an ultra wide band (UWB) bandpass filter with dual notch characteristics. The proposed filter is designed based on composite right/left handed (CRLH) transmission lines. The filter is having a compact size of 2.4 mm × 8.78 mm and printed on FR4 material with relative permittivity 4.4 with thickness 1.6 mm. The filter is constructed by series of strip lines, which forms interdigital capacitance and shunt inductors allowing both low and high frequencies of the UWB to pass. The selectivity in lower and higher parts of the UWB is achieved by the slots etched from the ground plane. The dual band notch is obtained at 4 GHz and 7 GHz using the L-shaped strip lines on both sides of the filter. The comparative analysis of the proposed UWB band pass filter without and with notch characteristics is presented with the help of the S11 and S21 curves.

Novel dual band patch antenna With Gap coupled composite right/left-handed transmission line

AbstractA novel low profile dual band patch antenna is presented. It consists of a composite right/left-handed transmission line (CRLH TL) unit cell gap coupled with the radiating edge of a rectangular patch antenna. The dual band behavior is achieved by coupling the zeroth order resonance mode of CRLH TL and TM10 mode of the patch antenna. It is shown that frequency ratio can be changed by varying the gap between the patch and CRLH TL unit cell. The proposed configuration enables frequency reconfigurability by changing the CRLH TL unit cell using a switch. A prototype of the antenna having frequency ratio f2/f1 = 1.08 is designed and fabricated. The proposed antenna shows measured S11 ≤ −10 dB bandwidth of 100 and 50 MHz at resonance frequencies of f1 = 4.84 and f2 = 5.22 GHz, respectively. A 2 × 2 dual band CRLH TL coupled patch array is also presented, showing more than 12.7 dBi gain at both resonance frequencies.

Design of broadband leaky‐wave antenna based on permeability‐negative transmission line

AbstractIn this paper, a planar broadband leaky‐wave antenna (LWA) has been designed to achieve a full‐space scanning property with a stable high gain. The proposed LWA consists of 9 permeability‐negative transmission line unit cells. With the use of the unit cell, the space harmonic with n = −2 mode in a wide frequency band is generated, and thus a scanning range from −90° to 0° is realized when one port of the LWA is excited and the other is connected to a matched load. Considering the symmetry of the proposed antenna structure, the scanning range from 0° to 90° can be achieved by exchanging the excitation port. A prototype was fabricated and measured. The experimental results show that the proposed LWA has an impedance bandwidth for SWR ≤ 2 from 11 to 17.5 GHz, a scanning range from −85° to +85°, and a stable gain of 10.7 ± 2 dB.

A novel ACPW-fed quad-band hybrid antenna for wireless applications

This paper presents a novel asymmetric coplanar waveguide-fed quad-band hybrid antenna for wireless applications. The proposed hybrid antenna combines a conventional monopole antenna and a zeroth-order resonator antenna to perform a dual-mode operation. The first mode is generated by a slotted monopole antenna, supporting the two higher resonances at about 3.5 and 5.8 GHz. The second mode is supported by loading a composite right-/left-handed transmission line unit cell near the slotted monopole, contributing to the two lower resonances at about 1.6 and 2.5 GHz. It is printed on an FR4 substrate with the overall dimensions of 40 mm × 24 mm × 1.6 mm. Experimental results demonstrate that it can cover the global positioning system (1.57–1.59 GHz), wireless local area network (2.4–2.485, 5.15–5.35, and 5.725–5.825 GHz), and worldwide interoperability for microwave access (2.5–2.69, 3.3–3.7, and 5.25–5.85 GHz) applications with monopole-like radiation patterns and acceptable gains.

Dual‐band planar antenna loaded with CRLH unit cell for WLAN/WiMAX application

A dual-band planar antenna based on composite right and left handed (CRLH) metamaterial is presented. The proposed antenna is comprised of a host folded planar monopole antenna and a CRLH transmission line unit cell. Due to another resonance frequency generated from the loaded CRLH unit cell, the presented antenna is actually a planar antenna with dual resonance bands at the centre frequency of 2.50 and 5.80 GHz, respectively, which can be regulated independently. The developed antenna also has different polarisations, the linear polarisation at the lower band and the circular polarisation at the upper resonance band. Rather than the complicated structure as before, this antenna is fabricated easily for the simple configuration without holes and the interdigital capacitances. The results of this study show that the reflection coefficient and radiation pattern have a good agreement between the simulation and measurement, the simulated relative bandwidth is 22.8% (2.22–2.79 GHz) and 10.8% (5.42–6.04 GHz), which meet the Wi-Fi/Worldwide Interoperability for Microwave Access (WiMAX) specification very well.

분산 CRLH 전송선로 4중 모드 공진기를 이용한 이중-광대역 대역통과 여파기 설계

본 논문은 CRLH (composite right/left handed) 전송선로 구조의 4중 모드 공진기를 이용하여 높은 대역간 격리도를 갖는 이중-광대역 대역통과 여파기를 설계하는 방법을 제안한다. CRLH 전송선로 구조를 해석하여 4중 모드 공진기의 s-패러미터와 공진 주파수를 유도하였다. 유도된 s-패러미터를 이용하여 새로운 구조의 이중-광대역 대역통과 여파기를 설계, 제작하였다. 측정 결과는 2.8-5.52 GHz, 9.68-12.26 GHz의 이중 통과대역에서 각각 1.08 dB, 2.01 dB의 삽입손실을 갖고, 6.34-8.42 GHz의 중간대역에서 38dB의 대역 격리도를 가져 설계 결과와 잘 일치하는 특성을 보여 주었다. This paper presents a dual-wideband bandpass filter (BPF) with high band-to-band isolation and skirt selectivity using distributed composite right/left-handed (CRLH) transmission line (TL) quad-mode resonators (QMRs). The results of the proposed distributed CRLH TL unit cell analysis are used to establish the scattering parameters and the resonance frequencies of the QMR constituting the dual-wideband BPF. A novel dual-wideband bandpass filter is designed and fabricated, using the derived scattering characteristics. The measured results show that the fabricated dual-wideband bandpass filter has an insertion loss of less than 1.08dB in the lower band, and of 2.01dB in the upper band, a bandwidth of 2.8-5.52GHz and 9.68-12.26GHz, and a band-to-band isolation of more than 38dB, from 6.34-8.42GHz.