Microstrip Technology Research Articles

Interference cancellation system of a microwave resonator filter for 4G and 5G applications

This paper aimed at designing a microwave resonator filter for use in 4G and 5G applications. A band resonator filter was designed and implemented using microstrip technology. Poor performance of a microstrip microwave resonator filter is due to spurious harmonics and unwanted frequencies which are always present and cause interferences of signals hindering effective communication. The coupling matrix was first obtained using polynomial functions of transmission and reflection coefficients. A cost function for optimization was developed and particle swarm optimization techniques were used to optimize the coupling matrix. The transversal matrix was developed and converted to the folded matrix for practical filter implementation. A bandpass filter was designed and simulated using high- frequency structure simulator software. Unwanted frequencies are eliminated by employing a novel square open loop resonator structure. The filter was designed to specification and the results show that unwanted frequencies were eliminated corresponding to the frequency of the outer resonator and therefore performs better than comparable filter.

Kinetic Inductance Detectors for the CADEx Experiment: Searching for Axions in the W-Band

This paper presents the detector developments for the Canfrac Axion Detection Experiment (CADEx), aiming at detecting dark matter axions and dark photons within the W-band. A proof of concept of the detection system is based on an array of lumped-element kinetic inductance detectors (LEKIDs). Microstrip technology is used as read-out scheme, and the ground plane acts as backshort for optimizing optical absorption in the W-band. A titanium/aluminum bilayer is used for ensuring detection below 100 GHz. The detector array design includes an inner active section consisting of 36 detectors for direct detection of the axion signal and an additional outer rim of 28 blind pixels for calibration purposes. The nanofabrication process and a preliminary cryogenic characterization are presented, being the results in good agreement with the frequency design. Measured devices exhibit coupling quality factors of the order of 6 × 104, internal quality factors above 105 and an estimated kinetic inductance of 3.3 pH/□.

Analysis, design, and optimization based on genetic algorithms of a highly efficient dual-band rectenna system for radiofrequency energy-harvesting applications

This paper gives an enhanced Rectenna design that operates at dual-band [2.45 and 5.8] GHz in the ISM (Industrial, Scientific, and Medical) band and is printed on an FR4-Epoxy substrate. This Rectenna design includes two proposed sub-designs for the receiving antenna and rectifier circuit based on the microstrip technology. The first sub-design concerns the microstrip patch antenna (MPA) described by its radiating element as a pentagonal, its ground being affected by a defective ground structure technique, and its polarization manner as circular polarization. This MPA design is analyzed, designed, optimized using genetic algorithms (GAs), simulated under CST MWS (i.e., computer simulation technology microwave studio), and confirmed by another software named HFSS (high-frequency structure simulator). The second sub-design concerns the microstrip rectifier circuit (MRC) that contains an input matching network based on a coupled-line impedance transformer strategy to achieve good adaptation between MPA and MRC, voltage doubler converter using an SMS7630 Schottky diode thanks to its high sensitivity, microstrip interdigital capacitor to mitigate the intrinsic losses due to the lumped elements, harmonic rejection filter based on a stepped-impedance low-pass filter to reject the unwanted harmonics generated by the non-linear behavior of SMS7630, and the resistive load that models the consumption of the system to be fed. This MRC is analyzed, designed, optimized using GAs, and simulated under ADS (Advanced Design System). The effectiveness of the proposed MPA is proven in terms of gain equals 3.06 dBi and 4.683 dBi at 2.45 GHz and 5.8 GHz respectively, and efficiency equals 95.13 % and 96.552 % at 2.45 GHz and 5.8 GHz respectively. The proposed MRC is effective in terms of efficiency at a lower input power value of about 97.18 % and 67.93 % at 2.45 GHz and 5.8 GHz respectively.

Using intrinsic‐resonance of an interdigitated microwave capacitor for detecting glyphosate‐based herbicide in water

AbstractGlyphosate‐based herbicides are the most used worldwide despite the fact that studies have shown their possible adverse effects on human health and the environment. Since the residues of these herbicides reach water bodies, their detection is considered an emergent research topic. In this work, the use of the intrinsic resonance of a microwave interdigitated capacitor fabricated on microstrip technology, is proposed for detecting the presence of glyphosate‐based herbicide in water. In addition, a sample holder is proposed to avoid the possible oxidation of the metal electrodes due to the direct contact with liquids. The proposed structure was designed to present its first intrinsic resonance at 1.95 GHz so that this resonance is shifted to 1.58 GHz when pure deionized water is used as sample. The sensor device was tested against 18 mixtures prepared with concentrations between 0% and 100% v/v of herbicide diluted in deionized water. Experimental measurements confirm that by using the intrinsic resonance parameters of the proposed structure, is possible to detect the presence of a glyphosate‐based herbicide. Finally, the results confirm the potential of the proposal as an alternative for real‐time, label‐free, and sensitive detection of glyphosate in water and they open the possibility of exploiting its use for the detection of other contaminants.

Medical Communication Systems Utilizing Optical Nanoantenna and Microstrip Technology

Many technical approaches were implemented in the antenna manufacturing process to maintain the desired miniaturization of the size of the antenna model which can be employed in various applied systems such as medical communication systems. Furthermore, over the past several years, nanotechnology science has rapidly grown in a wide variety of applications, which has given rise to novel ideas in the design of antennas based on nanoscale merits, leading to the use of antennae as an essential linkage between the human body and the different apparatus of the medical communication system. Some medical applications dealt with different antenna configurations, such as microstrip patch antenna or optical nanoantenna in conjugate with sensing elements, controlling units, and monitoring instruments to maintain a specified healthcare system. This study summarizes and presents a brief review of the recent applications of antennas in different medical communication systems involving highlights, and drawbacks with explores recommended issues related to using antennas in medical treatment.

Microstrip Passive Components for Energy Harvesting and 5G Applications

This review paper provides a comprehensive overview of microstrip passive components for energy harvesting and 5G applications. The paper covers the structure, fabrication and performance of various microstrip passive components such as filters, couplers, diplexers and triplexers. The size and performance of several 5G and energy harvester microstrip passive devices are compared and discussed. The review highlights the importance of these components in enabling efficient energy harvesting and high-speed communication in 5G networks. Additionally, the paper discusses the latest advancements in microstrip technology and identifies key research challenges and future directions in this field. Overall, this review serves as a valuable resource for researchers and engineers working on microstrip passive components for energy harvesting and 5G applications.

Creation of a soft circular patch antenna for bio-medical applications for 5G at frequency 2.45 GHz

In the medical field, efforts are currently focused on the development of devices implanted in the human body, to build a high-performance infrastructure and a working tool adapted to patients' needs. One such implanted device is the pacemaker, which is playing an increasingly important role in today's medicine. Moreover, in the general context of medical activities, we speak of telemedicine. This involves the transmission of medical information (images, reports, recordings) via antennae implanted or fixed on the human body, to obtain a remote diagnosis, specialist advice, constant patient monitoring, and a therapeutic decision. This paper presents a study and design of a circular flexible patch antenna with half-circle-shaped gaps on its sides and a slot on the opposite part of its feed; it is implemented on a bio-sourced type substrate intended for industrial, scientific, and medical applications. In addition, it is fed by microstrip technology, which features notches for impedance matching. In addition, this antenna offers improved performance compared with the literature.

Improving signal isolation in hybrid RF duplexer utilizing a band-pass filter

This study deals with a passive RF duplexer integrated with a two-notch band. To design the model, a band-pass filter is considered. Using micro-strip technology, the RF duplexer substation is simulated. It is a rectangular in parallel coupling with frequency bands of 1 and 5 GHz while existing three ports. Moreover, to enhance the impedance coefficient and decrease the admittance, the method of complementary paired resonators is taken into account. Furthermore, scattering parameters were used by the step impedance method to make an integrated monolayer substrate from signal branching in duplex mode. Thus, the band-pass filter making the frequency cut-off bands allows designing GSM-4G radars. The low cut-off microwave band is included in these bands at the 77 MHz central frequency and the second cut-off band for GSM-4G radars at the 437 MHz central frequency. The duplexer has the total dimensions of 14 mm × 99 mm and the presented RF duplexer is simulated in CST.

Tunable microstrip bandpass filter with constant absolute bandwidth using BST varactors and digitally tunable capacitors

Abstract In this paper, two second-order electronically tunable bandpass filters are presented. The filters are implemented in microstrip technology using barium–strontium–titanate (BST) varactors and digitally tunable capacitors (DTC) for tuning the frequency response of the bandpass filters. The filter realized using BST varactors has a 35% tuning range from 900 MHz to 1.275 GHz with an insertion loss variation from 3.1 to 2.6 dB. The absolute bandwidth is nearly constant over the entire tuning range, varying from 64 to 72 MHz (around ±5% variation). The filter realized using DTCs also has a 36% tuning range from 850 MHz to 1.225 GHz with an insertion loss variation from 3.1 to 1.5 dB. The absolute bandwidth is constant over the tuning range, varying from 88 to 98 MHz (around ±5% variation). The bandpass filters are tuned using a single control signal. The tunable bandpass filters are proposed for use in reconfigurable radios.

Design of balanced band pass filters with one transmission zero using an asynchronously coupled dual-mode resonator

A novel quasi-elliptic balanced bandpass filter (BBPF) designed on microstrip technology that uses Asynchronously Coupled Dual-Mode Resonator (ACDMR) is proposed. The filter is based on a novel Balanced Asynchronous Box (Basybox), which has five couplings and three resonators (two λ/2 resonators and a dual-mode grounded λ/2 resonator). By changing a conventional triplet with the use of dual-mode resonators, we can generate a non-resonant mode that generates a transmission zero (TZ). In addition, the filter has a balanced response. In this paper, full design methodology is presented along with a practical implementation. The filter has a center frequency in differential-mode of 950 MHz, a bandwidth of 53 MHz and a transmission zero at 975 MHz. For the common-mode, there is a rejection higher than 15 dB throughout the band up to 3 GHz. Good agreement between simulation and measurement is observed.

Регульований смуговий фільтр на основі кільцевих резонаторів для мікрохвильових застосунків

The paper presents the principle of a microwave adaptive band-pass filter based on the cascade of ring resonators. The filter is performed as a planar microstrip technology with thickness of around 1 mm to ensure compactness of the device. The ring resonators, being a part of metamaterials, can be considered as an equivalence of an oscillator and is conventionally used in the microwaves. While a quite number of the filters with predefined parameters are well-known, the adaptive filters the throughput and output characteristics of which can be adjusted depending on the input ones is the topical problematic nowadays and, at least, for the closest future. We have investigated in the paper the possibilities of adjustment the considered filter’s transmission characteristics through the ring design, distance between them, and discussed other features, which have impact. For example, it allows expanding of the filter bandwidth from 250 to 60 MHz for simultaneous change of a distance between the adjacent rings. We have suggested the approach how to do the filter time-dependent. A varactor diode inserted into the gap of the middle ring is controlled with an independent external source and can adjust the filter bandwidth from 80 up to 140 MHz for the varactor capacitance variation from 16 to 6 pF (bias voltage variation from 1 to 7 V) that covers the existing communication networks, such as mobile generations, Bluetooth, Wi-Fi, etc. and can be applied for modern smart technologies of the Internet-of-Things for a remote control. It becomes possible because different sensing elements, such as photodiodes, Hall effect sensors, photoresistors, etc., can be exploited as the aforementioned external source.

Design of Compact Parallel-Connected Chained Function Filters

The design of compact parallel-connected chained function filters is presented in this paper. The proposed filters will offer reduced sensitivity to manufacturing tolerance within the specified bandwidth in comparison to conventional Chebyshev filters for C-band applications. A new filtering function according to a chained configuration is derived for fourth-order filters, and the synthesis procedures are presented. To demonstrate the feasibility of this approach, the circuit simulation based on parallel-connected topology is performed in an advanced design system, while the design and simulation of a fourth-order filter in dielectric technology are carried out in high-frequency simulation software. The prototype of fourth-order microstrip topology is fabricated using open-loop resonators. The overall circuit size of the filter is 2.5 cm × 4 cm. The achieved simulation and measured insertion/return loss are 0.409 dB/20 dB and 2.674 dB/18.074 dB, respectively. Extensive sensitivity analysis is conducted to prove the fabrication tolerance of the filter. The reduced sensitivity of the proposed filter to manufacturing tolerance is fully demonstrated using an open-loop microstrip technology, and its reliability is proven by theoretical analysis. The prototype results in this research are validated and agree with the theoretical results. In terms of implementation, this design technique will be a very useful mathematical tool for any filter design engineer.

A Noncontact Planar Microstrip Sensor for Power Line Fault Detection

In this letter, a novel TM0 mode launcher is presented as a sensor for the fault detection on a single conductor line (SCL). The launcher is designed at 2.4 GHz frequency on an FR4 substrate with the microstrip technology. Simulated S-parameter results of the launcher are verified with the measured results of the fabricated prototype. Experiments are performed to demonstrate the signal propagation on a bent SCL, to measure the isolation between the launchers and to measure backward propagating signal. Open circuit fault location experiment is performed on a 6 m long cable using the Time domain reflectometry (TDR) technique. An average error of 0.15 m (5.04%) is observed in fault location. The proposed sensor is non-conductor-contact, non-intrusive, planar (16 cm*16 cm) and easy to install on the existing power lines for fault detection and power line communication.

Uncertainty quantification of additive manufacturing post-fabrication tuning of resonator-based microwave sensors

Reconfigurability, especially in terms of the ability of adjusting the operating frequency, has become an important prerequisite in the design of modern microwave components and systems. It is also pertinent to microwave sensors developed for a variety of applications such as characterization of material properties of solids or liquids. This paper discusses uncertainty quantification of additive-manufacturing-based post-fabrication tuning of resonator-based sensors implemented using a microstrip technology. Therein, the operating frequency is altered by adding metallic patches of a specific size determined by the full-wave electromagnetic (EM) model of the system. The reliability of setting up the center frequency depends on both the accuracy of the patch size (manually cut out of the copper tape), and its allocation with respect to the resonator. A rigorous statistical analysis of the patch size and its allocation errors is carried out, including a quantification of their joint effects on the sensor operating frequency. Furthermore, the analysis of a possibility of compensating the patch size inaccuracies through its appropriate positioning is conducted. The details of the proposed approach are explained using a complementary symmetric split ring resonator (CSSRR)-based sensor designed to operate in X and Ku bands with the tuning range between 10 GHz and 20 GHz. The optimized sensor's fundamental resonant frequency is 9.4 GHz, its exterior size is 25 × 30 mm2, the quality factor of the fabricated sensor is 29, and the sensitivity of the considered design is 1.1 GHz/mm with the measurement error is 0.1 percent. The obtained measurement data are indicative of a practical utility of the additive-manufacturing-based tuning technique, in particular, a possibility of reliable center frequency tuning under mild assumptions on the accuracy of manual preparation of the tuning patches. Furthermore, a practical tuning scheme has been developed and experimentally validated, which allows for a precise allocation of the operating frequency with the error not exceeding 0.01 GHz (or 0.1% in relative terms), all under assumptions of a manual preparation and placement of the tuning patch.

An Effective Design Scheme of Single- and Dual-Band Power Dividers for Frequency-Dependent Port Terminations

Flexible design schemes for single- and dual-band power dividers terminated in arbitrary port impedances are proposed in this paper. The proposed architecture provides the inherent impedance transformation to real, complex, and frequency-dependent complex impedances at the input and output port terminations. Furthermore, the proposed design is supported by flexible design procedures with independent design variables to enhance rapid prototyping in microstrip technology. It is demonstrated that the presence of independent design variables enhances the design flexibility for varied ranges of frequency and impedance transformation ratios. Two different prototypes, one each demonstrating single- and dual-band performances, are developed to validate the performance of the reported designs with real and frequency-dependent complex port impedances. The prototypes exhibit excellent agreements between the simulated and measured results. The single-band impedance transforming power divider (ITPD) possesses a low-amplitude imbalance of 0.5 dB, a phase imbalance of less than ±0.5∘, and an isolation of −26 dB at the design frequency of 5.8 GHz. The dual-band prototype also exhibits a low-amplitude imbalance of 0.5 dB and a phase imbalance of less than ±0.5∘ at both the design frequencies of 1 GHz and 2.6 GHz. The isolation is also better than −30 dB at both design frequencies. It is thus shown that the overall performance advances the state of the art in the design schemes of ITPDs.

Microstrip Copper Nanowires Antenna Array for Connected Microwave Liquid Sensors

In this contribution, a 25 GHz planar antenna, designed and realized in microstrip technology, is exploited as a lightweight and compact liquid sensor. The high working frequency allows minimization of the sensor dimension. Moreover, particular attention was paid to keeping the design cost low. Indeed, the frequency of 25 GHz is widely exploited for many applications, e.g., up to the last decade concerning radars and, recently, 5G technology. Available commercial antennas allowed minimization of the effort that is usually required to design the microstrip sensor. The antenna was in-house realized, and the microstrip Cu conductor was modified through controlled anodic oxidation in order to enhance the sensing features. The sensor capability of detecting the presence and concentration of ethanol in water was experimentally demonstrated. In detail, a sensitivity of 0.21 kHz/(mg/L) and an average quality factor of 117 were achieved in a very compact size, i.e., 18 mm × 19 mm, and in a cost-effective way. As a matter of fact, the availability of devices able to collect data and then to send the related information wirelessly to a remote receiver represents a key feature for the next generation of connected smart sensors.

An Advanced Array Configuration Antenna Based on Mutual Coupling Reduction

In this work, a microstrip antenna array that consists of 16 elements is designed at a frequency of 28 GHz, with a dimension of 35 mm × 33.5 mm and an operational bandwidth of 27.7–28.3 GHz. The idea is putting two antenna arrays next to each other on the same substrate and ground plane, as well as minimizing the overall size. This work presents a mutual coupling reduction for two arrays and studies the performance of the antennas through the suppression of surface wave propagation in a given frequency range. It proposed a new configuration for an artificial magnetic conductor (AMC) created by microstrip technology placed at a closed distance (0.3λ0) between the two antenna arrays. The improvement in the isolation between the two adjacent antenna arrays was studied according to the H-plane with a periodic unit cell of the AMC. The mutual coupling reduces to −40.0 dB at the operation frequency and isolation of 17 dB. The antenna array is also characterized by a good envelope correlation coefficient (ECC). The CST Microwave Studio electromagnetic solver was used to design, improve, and miniaturize the proposed configuration.

ISM Band 2.4 GHz Wearable Textile Antenna for Glucose Level Monitoring

Wearable technology has recently attracted much interest for various uses. An essential component of the wearable system is the wearable antenna. Textile and non-textile materials have both been used to create wearable antennas. Textile antennas are very useful and widely used nowadays, particularly in body-worn applications monitoring health parameters. Fabricated using microstrip technology, textile antennas have various benefits, including small size, lightweight, simple fabrication, and ease of wear. In this study, a microstrip antenna is created utilizing a substrate made of jeans. It works between 2.4 to 2.5 GHz in the ISM (industrial, scientific, and medical) band. High-frequency structure simulator (HFSS) software was used to simulate two antennas, one with an incomplete and the other with a complete ground plane. Wearable antennas can protect the body from the impacts of RF radiation by utilizing the entire ground plane principle. Results from a vector network analyzer were obtained for the fabricated antenna (VNA). This antenna's main function is to track blood glucose levels. Blood's dielectric characteristics change when blood sugar levels fluctuate, affecting the antenna’s output frequency. There are two ways to monitor glucose levels. One method requires placing a finger on an antenna patch, while the other involves fixing an antenna to a person's arm and detecting the output frequency fluctuation. The antenna's resonant frequency raises in reaction to increased blood glucose levels. Therefore, these textile antennas are a great choice for non-blood sample monitoring of blood glucose levels.

Design of high gain base station antenna array for mm-wave cellular communication systems

Millimeter wave (mm-Wave) wireless communication systems require high gain antennas to overcome path loss effects and thereby enhance system coverage. This paper presents the design and analysis of an antenna array for high gain performance of future mm-wave 5G communication systems. The proposed antenna is based on planar microstrip technology and fabricated on 0.254 mm thick dielectric substrate (Rogers-5880) having a relative permittivity of 2.2 and loss tangent of 0.0009. The single radiating element used to construct the antenna array is a microstrip patch that has a configuration resembling a two-pronged fork. The single radiator has a realized gain of 7.6 dBi. To achieve the gain required by 5G base stations, a 64-element array antenna design is proposed which has a bore side gain of 21.2 dBi at 37.2 GHz. The 8 × 8, 8 × 16, and 8 × 32 antenna array designs described here were simulated and optimized using CST Microwave Studio, which is a 3D full-wave electromagnetic solver. The overall characteristics of the array in terms of reflection-coefficient and radiation patterns makes the proposed design suitable for mm-Wave 5G and other communication systems.

Wideband Characterization of Microstrip Technology with Borofloat 33 and Some Classic Transparent Glasses

In this work, we made the technical qualification of borofloat 33 glass and also other much cheaper conventional glasses, associated with solid metallization by a broadband characterization method of microstrip technology based on the S-parameters. This made it possible to extract the electromagnetic parameters (dielectric permittivity, tangent loss) necessary for the design and construction of low visual impact antennas. The values of S11, S33, S12, and S34 are then extracted on vector network analyzer (VNA). The data of these measurement results are processed and the values of the loss tangent and the dielectric constant are thus measured with ADS software. We have obtained for the classical glass εr = 6.5 and tanδ = 0.0206; for the microscope glass εr = 6.15 and tanδ = 0.021 and at the end for the borofloat 33 glass εr = 4.5 and tanδ = 0.012.