scholarly journals A Ku-Band Foldable Reflectarray Based on a Maltese-Cross Microstrip Element

2021 ◽  
Vol 24 (4) ◽  
pp. 37-47
Author(s):  
S. V. Polenga ◽  
R. O. Ryazantsev ◽  
A. D. Poligina ◽  
R. M. Krylov ◽  
E. A. Litinskaya ◽  
...  
Keyword(s):  
Frequency Band ◽  
Satellite Communication ◽  
Experimental Studies ◽  
Single Layer ◽  
Phase Curve ◽  
Operating Frequency ◽  
Scanning Method ◽  
Operating Frequency Band ◽  
Phase Adjustment ◽  
Maltese Cross

Introduction. Reflectarrays have a number of design and functional advantages over their closest analogue - reflector antennas (RA). Although microstrip elements are the most preferred reflectarray elements, single-layer microstrip elements do not allow accurate phase control due to the limited phase adjustment range and a high phase slope. The use of multilayer elements significantly complicates the antenna design and increases its cost. The development of a single-layer element that allows more than 360° phase adjustment and a low phase curve slope is urgent.Aim. To develop a single-layer microstrip phase-correcting element with a phase adjustment range of more than 360° and to design a reflectarray on its basis for operation in satellite communication networks.Materials and methods. Numerical studies were carried out using finite element analysis and the finite-difference time-domain method. Radiation patterns were measured using the near-field scanning method in an anechoic chamber.Results. A phase-correcting element based on a single-layer Maltese cross-shaped microstrip element with close to linear dependence of element size on the phase of the reradiated wave and more than 360° phase adjustment range was developed. On the basis of the investigated element, a foldable reflectarray was designed. The reflector consists of four subarrays, which provide its compact folding for transportation. The results of experimental studies confirmed a high efficiency of the reflectarray, the gain of which is 1.5 dB lower than that of an identical overall dimensions RA in a 7 % operating frequency band. The operating frequency band of the reflectarray in 1 dB gain zone was 11 %.Conclusion. On the basis of a Maltese cross microstrip element, it is possible to implement a single-layer reflectarray with a more than 10 % frequency band. The developed prototype showed the possibility of creating highly efficient foldable reflectarrays for operation in satellite communication and television terminals.

scholarly journals An E-Band 21-dB Variable-Gain Amplifier with 0.5-V Supply in 40-nm CMOS

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 804
Author(s):  
Gibeom Shin ◽  
Kyunghwan Kim ◽  
Kangseop Lee ◽  
Hyun-Hak Jeong ◽  
Ho-Jin Song
Keyword(s):  
Power Consumption ◽  
Frequency Band ◽  
Noise Figure ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Operating Frequency ◽  
Variable Gain Amplifier ◽  
Variable Gain ◽  
Operating Frequency Band ◽  
Shunt Capacitors

This paper presents a variable-gain amplifier (VGA) in the 68–78 GHz range. To reduce DC power consumption, the drain voltage was set to 0.5 V with competitive performance in the gain and the noise figure. High-Q shunt capacitors were employed at the gate terminal of the core transistors to move input matching points for easy matching with a compact transformer. The four stages amplifier fabricated in 40-nm bulk complementary metal oxide semiconductor (CMOS) showed a peak gain of 24.5 dB at 71.3 GHz and 3‑dB bandwidth of more than 10 GHz in 68–78 GHz range with approximately 4.8-mW power consumption per stage. Gate-bias control of the second stage in which feedback capacitances were neutralized with cross-coupled capacitors allowed us to vary the gain by around 21 dB in the operating frequency band. The noise figure was estimated to be better than 5.9 dB in the operating frequency band from the full electromagnetic (EM) simulation.

scholarly journals A Multiband Printed Log-Periodic Dipole Array for Wireless Communications

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Giovanni Andrea Casula ◽  
Paolo Maxia
Keyword(s):  
Wireless Communications ◽  
Radiation Pattern ◽  
Frequency Band ◽  
Stop Band ◽  
Operating Frequency ◽  
Frequency Bands ◽  
Operating Frequency Band ◽  
Input Matching ◽  
Compact Size ◽  
Cst Microwave Studio

A multiband printed Log-periodic dipole array (LPDA) antenna for wireless communications is presented. The antenna has been designed starting from Carrel’s theory, optimized using CST Microwave Studio 2012, and then realized. The comparison between simulated and measured results shows that the proposed antenna can be used for wireless communications both in the S (2.4–3 GHz) and in the C (5.2–5.8 GHz) frequency bands, with very good input matching and a satisfactory end-fire radiation pattern. Moreover, it has a compact size, is very easy to realize, and presents an excellent out-of-band rejection, without the use of stop-band filters, thus avoiding interference out of its operating frequency band.

Tunable Balanced Bandpass Filter with High Common-mode Suppression Based on SLSRs

Frequenz ◽  
2017 ◽  
Vol 71 (11-12) ◽  
Author(s):  
Feng Wei ◽  
Xin Yi Wang ◽  
Dun Wei Liao ◽  
Xiao Wei Shi
Keyword(s):  
Frequency Band ◽  
Design Theory ◽  
Bandpass Filter ◽  
Design Procedure ◽  
Operating Frequency ◽  
Differential Mode ◽  
Common Mode ◽  
Operating Frequency Band ◽  
Mode Suppression ◽  
Transition Structures

AbstractA tunable balanced bandpass filter (BPF) with a good common-mode (CM) suppression based on slotline resonators is proposed in this letter. Two novel stub-loaded slotline resonators (SLSRs) terminated with varactors are designed to obtain tunable differential-mode (DM) responses. It is found that a high and wideband CM suppression can be achieved by employing balanced stepped-impedance microstrip-slotline transition structures. Moreover, the DM passbands are independent from the CM ones, which can significantly simplify the design procedure. To validate the design theory, a compact tunable balanced BPF with an operating frequency band ranging from 3.09 GHz to 3.6 GHz is designed and fabricated. The measured results are found to agree well with the simulated ones.

scholarly journals A Compact Slotted Patch Hybrid-Mode Antenna for Sub-6 GHz Communication

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Bei Huang ◽  
Mochao Li ◽  
Weifeng Lin ◽  
Jun Zhang ◽  
Gary Zhang ◽  
...  
Keyword(s):  
Frequency Band ◽  
Free Space ◽  
Operating Frequency ◽  
Impedance Bandwidth ◽  
Hybrid Mode ◽  
Average Gain ◽  
Operating Frequency Band ◽  
Rectangular Patch ◽  
Compact Size

A compact hybrid-mode antenna is proposed for sub-6 GHz communication. The proposed antenna is composed of a slotted rectangular patch, a feeding dipole, and a balun. Three modes are sequentially excited in a shared patch to achieve a compact size. A prototype antenna with a major size of 0.48 λ0 × 0.31 λ0 × 0.16 λ0 (λ0 is the wavelength in the free space at the center of the operating frequency band) is fabricated and measured. The measured results demonstrate an impedance bandwidth of 56.87% from 2.97 GHz to 5.33 GHz and an average gain of approximately 8.00 dBi with 1 dB variation in the operating frequency band of 3.0–5.0 GHz. The proposed antenna can be an element for microbase stations in sub-6 GHz communication.

8-Way Substrate Integrated Waveguide Power Divider

2013 ◽  
Vol 441 ◽  
pp. 137-140
Author(s):  
Wei Li ◽  
Li Qing Wang ◽  
Li Jia Chen ◽  
Xiao Wei Liu
Keyword(s):  
Frequency Band ◽  
Power Divider ◽  
Operating Frequency ◽  
Center Frequency ◽  
Substrate Integrated Waveguide ◽  
Operating Frequency Band ◽  
Equal Power

In this Paper, a 8-way Microwave Equal Power Divider with Substrate Integrated Waveguide Technology is Proposed and Designed . the Substrate Integrated Waveguide Power Divider with Metal pin Inductance is Investigated and Simulated. the Center Frequency is 9.5GHz, and the Operating Frequency Band is more than 1GHz. the Maximal Insert Loss is Less than 1dB from 9GHz to 10GHz. the Impedance of each Ports is 50Ω.

A Multi-Frequencies Micro-Electromagnetic Vibration Energy Harvester with Nonlinearity for Expanding the Frequency Band

2018 ◽  
Vol 18 (12) ◽  
pp. 8376-8380
Author(s):  
Yiming Lei ◽  
Xiaojuan Chen ◽  
Zhiyu Wen
Keyword(s):  
Frequency Band ◽  
Energy Harvester ◽  
Natural Frequencies ◽  
Operating Frequency ◽  
Energy Harvest ◽  
Vibration Energy ◽  
Vibration Energy Harvester ◽  
Operating Frequency Band ◽  
Electromagnetic Vibration ◽  
Structural Nonlinearity

In this paper, we proposed a multi-frequencies electromagnetic vibration energy harvester (EVEH) with a wider operating frequency band. The EVEH contains three different vibration picking-up systems with different natural frequencies. A broadened bandwidth was obtained by combining the structural nonlinearity of the vibration picking-up systems with the multi-frequencies, while the vibration energy harvest was increased by adopting two induction coils in the EVEH system. At an acceleration of 1.5g and frequencies of 45.6, 75 and 146.5 Hz, the peak–peak voltages of the prototype were 336, 270 and 39.8 mV, respectively. The corresponding bandwidths were 10.1, 7.8 and 4.2 Hz, respectively.

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