Modelling of Tunable CPW Structure Dielectric Phase Shifters

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.

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Analysis of Optimum Precoding schemes in Millimeter Wave System

Recent Advances in Computer Science and Communications ◽

10.2174/2666255813666200102124758 ◽

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.

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60 GHz beam-tilting coplanar slotted SIW antenna array

Frequenz ◽

10.1515/freq-2021-0069 ◽

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.

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