scholarly journals Coverage Analysis for Millimeter Wave Networks: The Impact of Directional Antenna Arrays

2017 ◽  
Vol 35 (7) ◽  
pp. 1498-1512 ◽  
Author(s):  
Xianghao Yu ◽  
Jun Zhang ◽  
Martin Haenggi ◽  
Khaled B. Letaief
Keyword(s):  
Millimeter Wave ◽  
Antenna Arrays ◽  
Directional Antenna ◽  
Coverage Analysis ◽  
The Impact

scholarly journals Temperature Characterization of Liquid Crystal Dielectric Image Line Phase Shifter for Millimeter-Wave Applications

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Henning Tesmer ◽  
Rani Razzouk ◽  
Ersin Polat ◽  
Dongwei Wang ◽  
Rolf Jakoby ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Millimeter Wave ◽  
Insertion Loss ◽  
Phase Shifter ◽  
Ground Plane ◽  
Temperature Dependent ◽  
Differential Phase ◽  
Dependent Behavior ◽  
The Impact ◽  
Temperature Dependent Behavior

In this paper we investigate the temperature dependent behavior of a liquid crystal (LC) loaded tunable dielectric image guide (DIG) phase shifter at millimeter-wave frequencies from 80 GHz to 110 GHz for future high data rate communications. The adhesive, necessary for precise fabrication, is analyzed before temperature dependent behavior of the component is shown, using the nematic LC-mixture GT7-29001. The temperature characterization is conducted by changing the temperature of the LC DIG’s ground plane between −10∘C and 80 ∘C. The orientation of the LC molecules, and therefore the effective macroscopic relative permittivity of the DIG, is changed by inserting the temperature setup in a fixture with rotatable magnets. Temperature independent matching can be observed, while the insertion loss gradually increases with temperature for both highest and lowest permittivity of the LC. At 80 ∘C the insertion loss is up to 1.3dB higher and at −10∘C it is 0.6dB lower than the insertion loss present at 20 ∘C. In addition, the achievable differential phase is reduced with increasing temperature. The impact of molecule alignment to this reduction is shown for the phase shifter and an estimated 85% of the anisotropy is still usable with an LC DIG phase shifter when increasing the temperature from 20 ∘C to 80 ∘C. Higher reduction of differential phase is present at higher frequencies as the electrical length of the phase shifter increases. A maximum difference in differential phase of 72∘ is present at 110 GHz, when increasing the temperature from 20 ∘C to 80 ∘C. Nevertheless, a well predictable, quasi-linear behavior can be observed at the covered temperature range, highlighting the potential of LC-based dielectric components at millimeter wave frequencies.

scholarly journals The Impact of Multi-Connectivity and Handover Constraints on Millimeter Wave and Terahertz Cellular Networks

2021 ◽  
pp. 1-1
Author(s):  
Mustafa F. Ozkoc ◽  
Athanasios Koutsaftis ◽  
Rajeev Kumar ◽  
Pei Liu ◽  
Shivendra S. Panwar
Keyword(s):  
Cellular Networks ◽  
Millimeter Wave ◽  
The Impact

scholarly journals A Tutorial on Optical Feeding of Millimeter-Wave Phased Array Antennas for Communication Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-22 ◽  
Author(s):  
Ivan Aldaya ◽  
Gabriel Campuzano ◽  
Gerardo Castañón ◽  
Alejandro Aragón-Zavala
Keyword(s):  
Millimeter Wave ◽  
High Speed ◽  
Phased Array ◽  
Path Loss ◽  
High Gain ◽  
Interference Avoidance ◽  
Amplitude Control ◽  
Phased Array Antennas ◽  
Array Antennas ◽  
The Impact

Given the interference avoidance capacity, high gain, and dynamical reconfigurability, phased array antennas (PAAs) have emerged as a key enabling technology for future broadband mobile applications. This is especially important at millimeter-wave (mm-wave) frequencies, where the high power consumption and significant path loss impose serious range constraints. However, at mm-wave frequencies the phase and amplitude control of the feeding currents of the PAA elements is not a trivial issue because electrical beamforming requires bulky devices and exhibits relatively narrow bandwidth. In order to overcome these limitations, different optical beamforming architectures have been presented. In this paper we review the basic principles of phased arrays and identify the main challenges, that is, integration of high-speed photodetectors with antenna elements and the efficient optical control of both amplitude and phase of the feeding current. After presenting the most important solutions found in the literature, we analyze the impact of the different noise sources on the PAA performance, giving some guidelines for the design of optically fed PAAs.

Design methods for ULA‐based directional antenna arrays by shaping the Cramér–Rao bound functions

2018 ◽  
Vol 12 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Minqiu Chen ◽  
Xingpeng Mao ◽  
Ran Guo ◽  
Ming‐Yang Cao ◽  
Yongtan Liu
Keyword(s):  
Antenna Arrays ◽  
Directional Antenna ◽  
Design Methods ◽  
Cramer Rao Bound
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