Tunable ceramic phase shifters and their applications

1993 ◽  
Author(s):  
Fathi Selmi ◽  
Raymond Hughes ◽  
Vijay K. Varadan ◽  
Vasundara V. Varadan
Keyword(s):  
Phase Shifters ◽  
Ceramic Phase

Ceramic phase-shifters for electronically steerable antenna systems

1991 ◽  
Author(s):  
Fathi Selmi ◽  
Deepak K. Ghodgaonkar ◽  
Raymond Hughes ◽  
Vasundara V. Varadan ◽  
Vijay K. Varadan
Keyword(s):  
Phase Shifters ◽  
Ceramic Phase ◽  
Steerable Antenna ◽  
Antenna Systems

The digital function filters – algorithms and applications

2013 ◽  
Vol 61 (2) ◽  
pp. 371-377
Author(s):  
M. Siwczyński ◽  
A. Drwal ◽  
S. Żaba
Keyword(s):  
Digital Filters ◽  
Phase Shifters ◽  
Square Root ◽  
Real Power ◽  
The Real ◽  
Distributed Parameters ◽  
Digital Modeling ◽  
Analysis And Synthesis ◽  
Basic Functions ◽  
Recursive Formulas

Abstract The simple digital filters are not sufficient for digital modeling of systems with distributed parameters. It is necessary to apply more complex digital filters. In this work, a set of filters, called the digital function filters, is proposed. It consists of digital filters, which are obtained from causal and stable filters through some function transformation. In this paper, for several basic functions: exponential, logarithm, square root and the real power of input filter, the recursive algorithms of the digital function filters have been determined The digital function filters of exponential type can be obtained from direct recursive formulas. Whereas, the other function filters, such as the logarithm, the square root and the real power, require using the implicit recursive formulas. Some applications of the digital function filters for the analysis and synthesis of systems with lumped and distributed parameters (a long line, phase shifters, infinite ladder circuits) are given as well.

Analysis of Optimum Precoding schemes in Millimeter Wave System

2020 ◽  
Vol 13 ◽  
Author(s):  
Divya Singh ◽  
Aasheesh Shukla
Keyword(s):  
Power Consumption ◽  
Millimeter Wave ◽  
Spectral Efficiency ◽  
Phase Shifter ◽  
Phase Shifters ◽  
Achievable Rate ◽  
Wave System ◽  
Digital To Analog Converter ◽  
Hybrid Precoding ◽  
Analog Converter

Background : Millimeter wave technology is the emerging technology in wireless communication due to increased demand for data traffic and its numerous advantages however it suffers from severe attenuation. To mitigate this attenuation, phased antenna arrays are used for unidirectional power distribution. An initial access is needed to make a connection between the base station and users in millimeter wave system. The high complexity and cost can be mitigated by the use of hybrid precoding schemes. Hybrid precoding techniques are developed to reduce the complexity, power consumption and cost by using phase shifters in place of converters. The use of phase shifters also increases the spectral efficiency. Objective: Analysis of Optimum Precoding schemes in Millimeter Wave System. Method: In this paper, the suitability of existing hybrid precoding solutions are explored on the basis of the different algorithms and the architecture to increase the average achievable rate. Previous work done in hybrid precoding is also compared on the basis of the resolution of the phase shifter and digital to analog converter. Results: A comparison of the previous work is done on the basis of different parameters like the resolution of phase shifters, digital to analog converter, amount of power consumption and spectral efficiency. Table 2 shows the average achievable rate of different algorithms at SNR= 0 dB and 5 dB. Table 3 also compares the performance achieved by the hybrid precoder in the fully connected structure with two existing approaches, dynamic subarray structure with and without switch and sub connected or partially connected structure. Table 4 gives the comparative analysis of hybrid precoding with the different resolutions of the phase shifter and DAC. Conclusion: In this paper, some available literature is reviewed and summarized about hybrid precoding in millimeter wave communication. Current solutions of hybrid precoding are also reviewed and compared in terms of their efficiency, power consumption, and effectiveness. The limitations of the existing hybrid precoding algorithms are the selection of group and resolution of phase shifters. The mm wave massive MIMO is only feasible due to hybrid precoding.

60 GHz beam-tilting coplanar slotted SIW antenna array

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamsakutty Vettikalladi ◽  
Waleed Tariq Sethi ◽  
Mohammed Himdi ◽  
Majeed Alkanhal
Keyword(s):  
Antenna Array ◽  
Phase Shifters ◽  
Impedance Bandwidth ◽  
Complex Geometries ◽  
Substrate Integrated Waveguide ◽  
60 Ghz ◽  
Central Frequency ◽  
Beam Tilting ◽  
Slotted Antenna ◽  
Passive Phase

Abstract This article presents a 60 GHz coplanar fed slotted antenna based on substrate integrated waveguide (SIW) technology for beam-tilting applications. The longitudinal passive slots are fed via associated SIW holes adjacent to the coplanar feed while the main excitation is provided from the microstrip-to-SIW transition. The antenna array achieves an impedance bandwidth of 57–64 GHz with gains reaching to 12 dBi. The passive SIW slots are excited with various orientations of coplanar feeds and associated holes covering an angular beam-tilting from −56° to +56° with an offset of 10° at the central frequency. The novelty of this work is; beam-tilting is achieved without the use of any active/passive phase shifters which improves the design in terms of losses and provide a much simpler alternative compared to the complex geometries available in the literature at the 60 GHz band.

scholarly journals Recent Development of Non-Contact Multi-Target Vital Sign Detection and Location Tracking Based on Metamaterial Leaky Wave Antennas

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3619
Author(s):  
Yichao Yuan ◽  
Chung-Tse Michael Wu
Keyword(s):  
Vital Sign ◽  
Complex Structure ◽  
Health Condition ◽  
Phase Shifters ◽  
Location Tracking ◽  
Radar Sensor ◽  
Leaky Wave ◽  
Multiple Targets ◽  
Microwave Radar ◽  
Sign Detection

Microwave radar sensors have been developed for non-contact monitoring of the health condition and location of targets, which will cause minimal discomfort and eliminate sanitation issues, especially in a pandemic situation. To this end, several radar sensor architectures and algorithms have been proposed to detect multiple targets at different locations. Traditionally, beamforming techniques incorporating phase shifters or mechanical rotors are utilized, which is relatively complex and costly. On the other hand, metamaterial (MTM) leaky wave antennas (LWAs) have a unique property of launching waves of different spectral components in different directions. This feature can be utilized to detect multiple targets at different locations to obtain their healthcare and location information accurately, without complex structure and high cost. To this end, this paper reviews the recent development of MTM LWA-based radar sensor architectures for vital sign detection and location tracking. The experimental results demonstrate the effectiveness of MTM vital sign radar compared with different radar sensor architectures.

scholarly journals Memristors as Candidates for Replacing Digital Potentiometers in Electric Circuits

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 181
Author(s):  
Ivo Marković ◽  
Milka Potrebić ◽  
Dejan Tošić
Keyword(s):  
Phase Shifter ◽  
Voltage Divider ◽  
Frequency Characteristics ◽  
Phase Shifters ◽  
Pass Filter ◽  
Electric Circuits ◽  
Digital Potentiometer ◽  
Memristive Circuits ◽  
Parasitic Effects ◽  
Additional Level

Digital potentiometers are substantial components for the design of many mixed-signal electronic circuits and systems. Their capability to program resistance value almost instantly provides hardware designers an additional level of freedom. Unfortunately, this feature is limited to DC and lower frequencies, due to parasitic effects. Nowadays, memristors as continuously tunable resistors are becoming candidates for potentiometer successors. Memristors are two-terminal non-volatile devices which have less significant parasitic effects and a wide resistance range. The memristance value can be changed on the fly. Using nanotechnology, memristor implementation has a nanoscale footprint with nanosecond transition between resistive states. In this paper, we present a comparison between the frequency characteristics of digital potentiometers and the only commercially available memristors. Memristor parasitic effects dominate at higher frequencies which extends the bandwidth. In order to present the advantages of memristive circuits, we have analyzed and implemented tunable circuits such as a voltage divider, an inverting amplifier, a high-pass filter, and a phase shifter. A commercially available memristor by KnowM Inc. is used for this purpose. Experimental results obtained by the measurements verify that a memristor has equal or better characteristics than a digital potentiometer. Memristive realizations of voltage dividers and inverting amplifiers have a wider bandwidth, while filters and phase shifters with a memristor have almost identical frequency characteristics as the corresponding realizations with a digital potentiometer.

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