GHz Wireless Communication Systems Research Articles

Design and Simulation of 1x4 Patch Array for Enhanced Gain

In contemporary wireless communication systems, antenna design plays a crucial role in achieving better performance metrics like gain, directivity, radiation efficiency, and appropriate impedance matching. In this work, a 1x4 array antenna operating at 2.4 GHz is designed and simulated. With an emphasis on single patch antennas and linear arrays with 1x2 and 1x4 components, beam steering in antenna array investigates the design, simulation, and analysis of antenna arrays at 2.4 GHz using CST Microwave Studio. In order to maximize performance, the project starts with the design of a single patch antenna. Important factors such as substrate material, patch dimensions, and feed mechanisms are examined. To improve gain, directivity, and bandwidth, 1x2 and 1x4 linear arrays are designed as an extension of the single patch design. The antennas are simulated using CST Microwave Studio, which offers comprehensive insights into their radiation patterns, impedance matching, and overall performance. Based on the simulations, it can be observed that a 1x4 array has substantially better gain and directivity when compared to a single patch. As a result, these arrays are more appropriate for applications that need more concentrated beams and greater coverage. Performance comparisons between the single patch, 1x2, and 1x4 arrays are included in the project's thorough study, along with a discussion of the trade-offs between design complexity, physical size, and performance advantages. The findings demonstrate the advantages of antenna arrays in improving 2.4 GHz wireless communication systems and provide insightful guidance for the creation of effective and high-performing antennas in this frequency range. The suggested antenna array exhibits encouraging performance in terms of parameters like gain, directivity, and efficiency, which qualifies it for use in particular applications including Internet of Things (IoT), wireless communication systems, and radar systems

A Full-Duplex 60 GHz Transceiver with Digital Self-Interference Cancellation

This paper presents the design and measurement of an IEEE 802.11ad standard compatible RF transceiver for 60 GHz wireless communication systems. In addition to the traditional half-duplex (HD) mode, this work supports full-duplex (FD) operations to deliver better channel utilization and faster response times for the system. The isolation between the transmitter and receiver from the architecture design to system integration for FD operations has been fully considered. A digital self-interference cancellation (DSIC) is implemented in MATLAB to verify the FD performance. The super-heterodyne architecture with an intermediate frequency (IF) of 12 GHz is designed to suppress the image frequencies without using extra filters. A flexible phase-locked loop (PLL) synthesizer provides a local oscillator (LO) frequency with a 2 kHz resolution. Other than the time division duplex (TDD) mode used in the conventional 60 GHz system, a wide-bandwidth baseband digital variable-gain amplifier (DVGA) with a 3 dB bandwidth of more than 4 GHz also supports frequency division duplex (FDD) operations. The transceiver chip is fabricated using the Tower Jazz 0.18 µm SiGe BiCMOS process. With an on-board antenna, the transceiver covers all four channels in the 802.11ad standard, with MCS-12 (7.04 Gbps under 1.76 GSym/s and 16-QAM) under 1.5 m. In the proposed system design, the RF frontend-based self-interference (SI) suppression from the local transmitter to receiver LNA is around 54 dB. To achieve a practical FD application, the SI is further suppressed with the help of a digital SI compensation. The measured power consumption for the transmitter and receiver configurations are 194 mW and 231 mW, respectively, in HD mode and 398 mW for the FDD or FD operation mode.

Design and Simulation of Frequency-Hop for 2.4 GHz Wireless Communication System

Design and Simulation of Frequency-Hop for 2.4 GHz Wireless Communication System

A Self-Decoupling Technique to Realize Dense Packing of Antenna Elements in MIMO Arrays for Wideband Sub-6 GHz Communication Systems.

A self-decoupled technique is described that enables the radiating elements in the antenna array to be densely packed for multiple-input multiple-output (MIMO) wireless communications systems. High isolation between the adjacent antenna elements is obtained by fixing the radiating elements in an orthogonal configuration with respects to each other. Current from the adjacent ports cancels their impact which results in low mutual coupling. The additional benefit of this configuration is realizing a densely packed array. The ground plane of each radiating element on the array board itself are isolated to mitigate surface wave propagations to suppress mutual coupling between the antenna elements. The radiating elements are based on a modified edge-fed circular patch antenna that includes a curved slot line and open-circuited stub to widen the array's impedance bandwidth with no impact on the antenna's footprint size. The proposed technique was verified with the design of an antenna array of matrix size 4 × 4 centered at 3.5 GHz. The array had a measured impedance bandwidth of 4 GHz from 1.5 GHz to 5.5 GHz, which corresponds to a fractional bandwidth of 114%, peak gain of 3 dBi and radiation efficiency of 84%. Its average diversity gain and envelope correlation coefficient (ECC) over its operating band are 9.6 dB and <0.016, respectively. The minimum isolation achieved between the radiating elements is better than 15 dB. The dimensions of the array are 0.4 × 0.4 × 0.039λ_g^3. The proposed array has characteristics suitable for sub-6 GHz wireless communication systems.

Gain and isolation enhancement of a wideband MIMO antenna using metasurface for 5G sub-6 GHz communication systems

This work proposes a compact metasurface (MS)-integrated wideband multiple-input multiple-output (MIMO) antenna for fifth generation (5G) sub-6 GHz wireless communication systems. The perceptible novelty of the proposed MIMO system is its wide operating bandwidth, high gain, lower interelement gap, and excellent isolation within the MIMO components. The radiating patch of the antenna is truncated diagonally with a partially ground plane, and a metasurface has been employed for enhancing the antenna performance. The suggested MS integrated single antenna prototype has a miniature dimension of 0.58λ × 0.58λ × 0.02λ. The simulated and measured findings demonstrate a wideband characteristic starting from 3.11 to 7.67 GHz including a high realized gain of 8 dBi. The four-element MIMO system has been designed by rendering each single antenna orthogonally to one another while retaining compact size and wideband properties between 3.2 and 7.6 GHz. The suggested MIMO prototype has been designed and fabricated on a low loss Rogers RT5880 substrate with a miniature dimension of 1.05λ × 1.05λ × 0.02λ and its performance is evaluated using a suggested 10 × 10 array of a square enclosed circular split ring resonators within the same substrate material. The inclusion of the proposed metasurface with a backplane significantly reduces antenna backward radiation and manipulates the electromagnetic field, thus improving the bandwidth, gain and isolation of MIMO components. The suggested 4-port MIMO antenna offers a high realized gain of 8.3 dBi compared to existing MIMO antennas with an excellent average total efficiency of 82% in the 5G sub-6 GHz spectrum and is in good accordance with measured results. Furthermore, the developed MIMO antenna exhibits outstanding diversity characteristics in respect of envelope correlation coefficient (ECC) less than 0.004, diversity gain (DG) close to 10 dB (> 9.98 dB) and high isolation between MIMO components (> 15.5 dB). Therefore, the proposed MS-inspired MIMO antenna substantiates its applicability for 5G sub-6 GHz communication networks.

Enhanced radiation gain and efficiency of a metamaterial‐inspired wideband microstrip antenna using substrate integrated waveguide technology for sub‐6 GHz wireless communication systems

AbstractThis paper shows a technique to enhance the radiation gain and efficiency of metamaterial (MTM) inspired planar antenna using substrate integrated waveguide (SIW) technology for sub‐6 GHz wireless communication systems. The antenna consists of MTM unit‐cells comprising series interdigital‐capacitor and short‐circuited spiral stub. The proposed antenna behaves like a leaky wave antenna. In the transmission mode the input signal propagating along the antenna structure and leaks energy. The performance of the antenna is shown to enhance by embedding a column of metallic vias between the MTM unit‐cells. This technique has no impact on the size of the antenna. The antenna was constructed on a standard FR4 dielectric substate. It had dimensions of 23.2×6.4×0.8 mm3 and had a wide operational frequency range 1.8 GHz from 3.0–4.8 GHz. After applying SIW the average gain and efficiency of the antenna were 5.8 dBi and 78%, respectively, which is an improvement of 2 dBi and 21% across 3–4.8 GHz.

Reduction of Mutual Coupling between Radiating Elements of an Array Antenna Using EBG Electromagnetic Band Structures

In this paper, a new array antenna configuration based on Electromagnetic Band Gap (EBG) structures has been proposed for 3.5GHz wireless communication systems. The proposed slotted EBG structure, high impedance surface (SHI), consists of three squares and a square ring deposited on a substrate (Rogers RO4350) which has a relative permittivity of 10.2 and a thickness of 1.27mm. Initially a matrix of 3×7 unit cells of EBG structures is introduced between two patches of an array and then a matrix of 3×14 unit cell of EBG structures is integrated between eight patches, which resonate around 3.5GHz (Wi MAX). The insertion of these structures between the radiating elements of an array antenna reduces the mutual coupling and antenna dimensions by approximately (8dB, 11%) and (12 dB, 5%) respectively for two, eight elements array antenna. In addition, the directivity has been slightly improved in the presence of EBG structures, from 4.52dB to 6.09dB for a two-element array antenna, and from 8.18dB to 8.4dB for an eight-element antenna.

Threshold Selection Algorithm Based on Skewness and Standard Deviation Using Back Propagation Artificial Neural Networks in the 60GHz Wireless Communication Systems

Accurate localization has gained significant interest in the field of sensor networks, impulse radio 60GHz signals which is low cost, low complexity are even much more practical for ranging, localization and tracking systems because of the high time and multipath resolution and so on. Typically, accurate Time of Arrival (TOA) estimation of the 60GHz signals is very important. In order to improve the precision of the TOA estimation, a new threshold selection algorithm using Back Propagation Artificial Neural Networks (BP-ANN) is proposed which is based on a joint metric of Skewness and Standard Deviation after Energy Detection. The best threshold based on the signal-to-noise ratio (SNR) is investigated and the effects of the integration period and channel model are examined. Simulation results are presented which show that for the IEEE802.15.3c channel models CM1.1 and CM2.1, the proposed BP-ANN algorithm provides better precision and robustness in both high and low SNR environments than other ED-based algorithms.

Performance Analysis of OFDM 60GHz System and SC-FDE 60GHz System

In this paper, the performance of 60GHz wireless communication system with SC and OFDM is studied, the models of OFDM 60GHz system and SC 60GHz frequency domain equalization (SC-FDE) system are established, and the bit error rate (BER) performance of OFDM 60GHz system and SC-FDE 60GHz system in 802.15.3c channels is compared. The simulation results show that SC-FDE 60GHz system has a slight advantage over OFDM system in line-of-sight (LOS) channels, while OFDM 60GHz system has a slight advantage over SC-FDE system in non-line-of-sight (NLOS) channels. For 60GHz system, OFDM 60GHz system has a slight advantage over SC-FDE system in overcoming multipath fading, but the performance of both is close whether in the LOS or NLOS case.

A PLANAR END-FIRE ANTENNA WITH WIDE BEAMWIDTH FOR 60 GHZ APPLICATIONS

A novel 60 GHz end-fire antenna for point-to-multipoint applications is presented. The prototype of this antenna is a dipole structure with a wide beamwidth. Then, the radiators are tilted with the ground is also modified to improve its directive gain while maintaining wide signal coverage. The antenna has a compact size of 10 mm× 7m m× 0.254 mm. Measured results show that the antenna has favorable properties of 3-dB beamwidth up to 150 ◦ at 60 GHz, S11 less than �10 dB and stable gain of 5.9 to 6.8 dBi over 57 to 64 GHz, where these characteristics denote it fitting for 60 GHz wireless communication systems.

Energy Detector vs. Matched Filtering in 60GHz Indoor Wireless Communications System

Whether can the received signal be done with in an even better fashion or not, which is a key factor that can make impact on the accuracy of the ranging and positioning in the 60GHz wireless communication system. There are two mainstream algorithms that may be used for dealing with the signals, which can be segmented into Matched Filtering algorithm and Energy Detection algorithm according to the principle. In order to get the signal processing algorithm that is more suitable for 60GHz millimeter wave. These two algorithms were studied deeply from five aspects respectively such as the distance between nodes, sampling frequency, normalized threshold, the integration period, Signal-to-Noise Ratio. The previous Maximum Energy Selection algorithm and fixed Threshold-Crossing algorithm were compared with the Matched Filtering algorithm in the IEEE 802.15.3c standard indoor channel models. Performance results that are presented verify that it is obvious to improve the accuracy of ranging so long as the received signal is better processed.

Compact 60 GHz LTCC balun bandpass filter with two transmission zeroes

A new balun–bandpass filter with a quasi-elliptic response for 60 GHz wireless communication systems is proposed. It is designed in the form of a substrate integrated waveguide (SIW) and fabricated with the standard low-temperature co-fired ceramic (LTCC) technology. Both simulated and experimental results are provided, which have good agreement. The results indicate that the proposed balun filter has a good balance performance with <1.1 dB amplitude imbalance and better than 3.4° phase imbalance, compact size, as well as high selectivity.

A 60 GHZ END-FIRE HIGH-GAIN TAPERED SLOT ANTENNA WITH SIDE-LOBE SUPPRESSION

A simple end-fire high-gain antenna with side-lobe level suppression is proposed for 60 GHz technology in this paper. The antenna has a tapered slot radiation patch which is obtained by subtracting a quarter of ellipse from a bigger quarter. Two reflecting circle units (RCU) are located at both sides of radiant patch to suppress side-lobe level of radiation patterns. The antenna has a simple two-layered planar structure with on via and is fabricated on a Rogers 4350 substrate with a compact size of 15 mm × 15 mm. Simulated and measured results match well, and both show its good characteristics of impedance matching, stable radiation patterns and steady peak gains above 10 dBi across 57-64 GHz, which makes it fit 60 GHz wireless communication systems.

Coach-Swimmer Communications Based on Wrist Mounted 2.4GHz Accelerometer Sensor

Two way real time communications during swimming is important for coaches and swimmers in order to reach optimum performance. This paper presents a 2.4GHz wireless communication system to send acceleration data to a coach tablet at the pool side and allow active interactions between swimmers and their coaches. The radio frequency signal does not propagate effectively underwater because of the high attenuation. Therefore the wireless transmitter sends data only when the swimmer's wrist is outside the water. The y-axis acceleration data provides stroke rate SR, stroke length and swim velocity. The experimental results showed that the link is operational 28% per stroke in freestyle swimming. This is more than enough to send important data from the swimmer and reply with the coach's feedback.

Study of High-Accurate Frequency Estimation in 60GHz Wireless Communication System

A high-accurate frequency estimation algorithm is proposed in the 60GHz OFDM wireless communication system. The phase offset is caused by the carrier frequency offset, and its accumulation has a linear relationship in the time. So the preamble sequence phase can be obtained by the algorithm in this paper, and then the carrier frequency offset value is calculated by the linear regression theory. The 60GHz wireless communication system simulation platform is established. In the platform, the algorithm is simulated with different carrier frequency offset, and the algorithm estimation performance is contrasted with the traditional algorithm. The results show that accuracy of the algorithm has 30dB higher than the auto- correlation algorithm, and that the BER performance of the algorithm is the same as witch in the case of no frequency offset. So the high-accuracy of frequency offset estimation is proposed by the algorithm in the 60GHz wireless communication.

A Pulse-Based 60GHz Ranging System

60GHz signal has very high time resolution and multipath resolution, thus having the potential of achieving high accuracy ranging and positioning at centimeter level or even millimeter level. This technology has great application value in fields like indoor robot navigation, hazardous area monitoring and accurate positioning. In this paper, after designing the pulse-based 60GHz wireless communication system, we proposed a pulse-based 60GHz ranging system. Theoretical analysis and simulations demonstrate that the proposed system can achieve good ranging performance.

Channel Estimation on 60GHz Wireless System Based on Subspace Pursuit

Due to the channel with characteristic of sparse multi-path in the 60 GHZ wireless communication system, the channel estimation problem can be attributed to that of sparse signals recovery. And with the consideration of the subspace pursuit (SP) algorithm is superior to the orthogonal matching pursuit (OMP) at reconstruction precision, the channel estimation technique based on the SP algorithm is presented in the 60 GHZ wireless communication system, First, design the OFDM multi-carrier modulation communication system. Then, establish the channel estimation mathematical model with indoor Line-of-sight. Finally, complete the reconstruction of sparse signals using SP algorithm. The experimental results and comparison analysis show that the presented technique based on the SP algorithm provides better channel estimation performances in the same pilot conditions, and it is superior to the technique based on OMP algorithm and the technique based on least square (LS) algorithm.

A COMPACT MICROSTRIP PATCH ANTENNA WITH RECONFIGURABLE FEED NETWORK FOR POLARIZATION DIVERSITY

A compact reconfigurable four-feeding microstrip antenna with polarization diversity is presented in this paper. With four triangle-shaped elements as the radiation patch, the proposed antenna can achieve good impedance match for linear polarization (LP), left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). A four-way power divider made by three Wilkinson power dividers and interconnected with PIN diodes is designed to feed the four elements. By controlling the states of the diodes, the antenna can produce LP, LHCP and RHCP. By using T-shaped slots on the patch and back to back geometry, a compact size of 0.6λ0 × 0.6λ0 × 0.02λ0 is achieved. The impedance bandwidth of LP is about 80 MHz (3.3%), while the usable bandwidths (overlap of impedance bandwidth and AR bandwidth) of LHCP and RHCP are about 370 MHz (15%) and 250 MHz(10%). The average gain for LP is −2.1 dB, and that for CP is −3.3 dB. This reconfigurable patch antenna with switchable polarization has good performance and simple structure, which can be used for 2.4 GHz wireless communication systems.

A Polarization Reconfigurable Patch Antenna With Loop Slots on the Ground Plane

This letter proposes a reconfigurable microstrip patch antenna with polarization states being switched among linear polarization (LP), left-hand (LH) and right-hand (RH) circular polarizations (CP). The CP waves are excited by two perturbation elements of loop slots in the ground plane. A p-i-n diode is placed on every slot to alter the current direction, which determines the polarization state. The influences of the slots and p-i-n diodes on antenna performance are minimized because the slots and diodes are not on the patch. The simulated and measured results verified the effectiveness of the proposed antenna configuration. The experimental bandwidths of the -10-dB reflection coefficient for LHCP and RHCP are about 60 MHz, while for LP is about 30 MHz. The bandwidths of the 3-dB axial ratio for both CP states are 20 MHz with best value of 0.5 dB at the center frequency on the broadside direction. Gains for two CP operations are 6.4 dB, and that for the LP one is 5.83 dB. This reconfigurable patch antenna with agile polarization has good performance and concise structure, which can be used for 2.4 GHz wireless communication systems.

Capacity of 60 GHz Wireless Communication Systems over Fading Channels

This paper considers the channel capacity of 60GHz wireless communications systems over Rayleigh fading channels and Ricean fading channels. The SNR and therefore capacity varies according to the communication distance. The capacity is presented for line-of-sight (LOS) and non-line-of-sight (NLOS) channels given based on a 60GHz link budget model. Phase shift keying (PSK) modulation is considered under FCC power constraints for the unlicensed 59-64GHz radio spectrum. The channel capacity over Rayleigh fading channels is compared with the capacity in additive white Gaussian noise channels. The paper also investigates the channel capacity of 60GHz wireless communications systems over Ricean fading channels and gives the channel capacity compariasion with q-ary PSK modulation over Ricean fading channel, AWGN channel and Rayleigh channel when the SNR per symbol is given. The results show that a 60GHz wireless system is more suitable for short range communications less than 100 meters rather than long distances