Designing 6–18 GHz Microstrip Filters with Removing Unwanted Upper and Lower Band Frequency Responses and with Arbitrary Load Impedance Matching

2020 ◽  
pp. 2150131
Author(s):  
Alireza Sharifi
Keyword(s):  
Impedance Matching ◽  
Computer Code ◽  
Optimization Method ◽  
Ultra Wideband ◽  
Load Impedance ◽  
Band Frequency ◽  
Arbitrary Load ◽  
Frequency Responses ◽  
Full Wave ◽  
Wave Methods

In this paper, Ultra-Wideband (UWB) filters at 6–18[Formula: see text]GHz are designed that can reduce undesired frequency responses at lower and upper frequency bands to less than [Formula: see text]20[Formula: see text]dB. Arbitrary load impedances are considered in the design of these filters. The structure of these filters is the combination of microstrip band-pass filters and Defected Ground Structures (DGSs) with multiple sections. The optimum circuit dimensions are calculated using a computer code which implements the Least Mean Squares (LMS) optimization method. Two design examples are included to illustrate this method. In these examples, eight-section DGS structures are employed to eliminate the unwanted upper frequency band responses. To ensure the correct performance of the designed filters, they are analyzed using full-wave methods and fabrication and the results of the measurement or full-wave analysis shows good agreement with the results of the computer code and the circuit model simulations.

scholarly journals Fast Hierarchical Optimization Method for High Speed Channel Design Using Channel Operating Margin

2020 ◽  
Author(s):  
Bo Pu
Keyword(s):  
High Speed ◽  
Impedance Matching ◽  
Optimization Method ◽  
Design Flow ◽  
Hierarchical Optimization ◽  
Physical Parameters ◽  
Channel Design ◽  
Horizontal Structure ◽  
Full Wave ◽  
Operating Margin

This paper proposes a design flow for channel design by a fast hierarchical optimization method based on Channel Operating Margin (COM). Unlike the common design of experiment (DOE), the method performs the design by a hierarchical flow in the level of electrical characteristic while not the usual horizontal structure of physical parameters. It significantly reduces the number of huge samples used in DOE, and thus is able to offer a fast estimation approach for channel in the early design period. In each stage of the vertical flow, the electrical properties of component are extracted by 2.5D or 3D full wave simulator, and thus ensure the accuracy of the channel design. Design strategy for the most crucial discontinuity, Via, to achieve an impedance matching is addressed. Package effect on the COM is also discussed as a reference for adjusting the 3dB criterion of COM in the future.

scholarly journals Fast Hierarchical Optimization Method for High Speed Channel Design Using Channel Operating Margin

2020 ◽  
Author(s):  
Bo Pu
Keyword(s):  
High Speed ◽  
Impedance Matching ◽  
Optimization Method ◽  
Design Flow ◽  
Hierarchical Optimization ◽  
Physical Parameters ◽  
Channel Design ◽  
Horizontal Structure ◽  
Full Wave ◽  
Operating Margin

This paper proposes a design flow for channel design by a fast hierarchical optimization method based on Channel Operating Margin (COM). Unlike the common design of experiment (DOE), the method performs the design by a hierarchical flow in the level of electrical characteristic while not the usual horizontal structure of physical parameters. It significantly reduces the number of huge samples used in DOE, and thus is able to offer a fast estimation approach for channel in the early design period. In each stage of the vertical flow, the electrical properties of component are extracted by 2.5D or 3D full wave simulator, and thus ensure the accuracy of the channel design. Design strategy for the most crucial discontinuity, Via, to achieve an impedance matching is addressed. Package effect on the COM is also discussed as a reference for adjusting the 3dB criterion of COM in the future.

Angle and polarization-independent miniaturized UWB FSS design

2021 ◽  
pp. 1-9
Author(s):  
Yanning Yuan ◽  
Yuchen Zhao ◽  
Xiaoli Xi
Keyword(s):  
Design Method ◽  
Incident Angle ◽  
Stop Band ◽  
Single Layer ◽  
Wireless Systems ◽  
Frequency Selective Surface ◽  
Ultra Wideband ◽  
Band Frequency ◽  
Gain Enhancement ◽  
Polarization Independent

Abstract A single-layer ultra-wideband (UWB) stop-band frequency selective surface (FSS) has several advantages in wireless systems, including a simple design, low debugging complexity, and an appropriate thickness. This study proposes a miniaturized UWB stop-band FSS design. The proposed FSS structure consists of a square-loop and metalized vias that are arranged on a single layer substrate; it has an excellent angle and polarization-independent characteristics. At an incident angle of 60°, the polarization response frequencies of the transverse electric and magnetic modes only shifted by 0.003 f0 and 0.007 f0, respectively. The equivalent circuit models of the square-loop and metallized vias structure are analysed and the accuracy of the calculation is evaluated by comparing the electromagnetic simulation. The 20 × 20 array constitutes an FSS reflector with a unit size of 4.2 mm × 4.2 mm (less than one-twentieth of the wavelength of 3 GHz), which realizes an UWB quasi-constant gain enhancement (in-band flatness is <0.5 dB). Finally, the simulation results were verified through sample processing and measurement; consistent results were obtained. The FSS miniaturization design method proposed in this study could be applied to the design of passband FSS (complementary structure), antennas and filters, among other applications.

Selectivity and in-band impedance enhancement of a compact slot antenna with defected ground structures

2019 ◽  
Vol 11 (10) ◽  
pp. 1010-1016
Author(s):  
Hailong Yang ◽  
Xiaoli Xi ◽  
Lili Wang ◽  
Yuchen Zhao ◽  
Xiaomin Shi
Keyword(s):  
Reflection Coefficient ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Band Edge ◽  
Slot Antenna ◽  
Defected Ground Structure ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Uwb Antennas ◽  
Low Pass

AbstractIn this study, a new ultra-wideband (UWB) band-edge selectivity antenna with a modified radiation slot using defected ground structure (DGS) is presented to obtain bandpass filtering reflection coefficient and gain performance. The well-designed DGS is designed on backside metallic of the substrate and can be seen as a low-pass filter that provides a good roll-off at a higher frequency. By connecting the DGS and the stepped slot and making them merge with each other, good cut-off property in the upper passband and better in-band impedance characteristics are obtained. Measured results show that the proposed design not only shows good band-edge selectivity in reflection coefficient and gain performance but also has a good impedance matching of −13.5 dB reflection coefficients and a good radiation efficiency of 90% in the operating frequencies. The measured bandwidth defined with the reflection coefficient less than −10 dB is from 3.1–11.2 GHz. Furthermore, the size of the filtering UWB antenna is 22 mm × 12 mm, which is smaller than many individual UWB antennas and UWB filters.

Miniature UWB Filter Using Three-Quarters Wavelength Resonator with Direct-Connected Feed Method

2012 ◽  
Vol 571 ◽  
pp. 721-724
Author(s):  
Cai Peng
Keyword(s):  
Transmission Lines ◽  
Linear Structure ◽  
Ultra Wideband ◽  
Input Output ◽  
Transmission Zeros ◽  
Full Wave ◽  
Quarter Wavelength ◽  
Ring Structures ◽  
Loss Characteristic ◽  
Better Than

A miniature ultra-wideband (UWB) bandpass filter using three-quarters wavelength resonators is presented in this paper. Direct-connected feed method is employed between the input/output ports and the resonators in order to overcome the shortcomings due to the gap-coupled feed method and produce two transmission zeros in the lower and upper stopbands. On the other hand, two quarter-wavelength matching transmission lines are introduced to the input/output ports to improve the reflection loss characteristic in the passband of the filter. In addition, the resonators are folded to be open ring structures, which are more miniaturized than the conventional linear structure. As a consequence, the filter is compact in size and exhibits good performance. The filter is successfully realized in theory and verified by full wave EM simulation, and simulated frequency response results show that the fabricated filter has an insertion loss of better than 1dB in the passband and two rejections of greater than 25dB in most of the stopbands.

scholarly journals Compact Liquid Crystal Based Tunable Band-Stop Filter with an Ultra-Wide Stopband by Using Wave Interference Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Longzhu Cai ◽  
Huan Xu ◽  
Daping Chu
Keyword(s):  
Liquid Crystal ◽  
Impedance Matching ◽  
Wide Frequency Range ◽  
Ultra Wideband ◽  
New Wave ◽  
Wave Interference ◽  
Rejection Level ◽  
Band Stop Filter ◽  
The Individual ◽  
Uwb Applications

A wave interference filtering section that consists of three stubs of different lengths, each with an individual stopband of its own central frequency, is reported here for the design of band-stop filters (BSFs) with ultra-wide and sharp stopbands as well as large attenuation characteristics. The superposition of the individual stopbands provides the coverage over an ultra-wide frequency range. Equations and guidelines are presented for the application of a new wave interference technique to adjust the rejection level and width of its stopband. Based on that, an electrically tunable ultra-wide stopband BSF using a liquid crystal (LC) material for ultra-wideband (UWB) applications is designed. Careful treatment of the bent stubs, including impedance matching of the main microstrip line and bent stubs together with that of the SMA connectors and impedance adaptors, was carried out for the compactness and minimum insertion and reflection losses. The experimental results of the fabricated device agree very well with that of the simulation. The centre rejection frequency as measured can be tuned between 4.434 and 4.814 GHz when a biased voltage of 0–20 Vrms is used. The 3 dB and 25 dB stopband bandwidths were 4.86 GHz and 2.51 GHz, respectively, which are larger than that of other recently reported LC based tunable BSFs.

scholarly journals CMOS Ultra-Wideband Low Noise Amplifier Design

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
K. Yousef ◽  
H. Jia ◽  
R. Pokharel ◽  
A. Allam ◽  
M. Ragab ◽  
...  
Keyword(s):  
Impedance Matching ◽  
Cmos Technology ◽  
Low Noise ◽  
Low Noise Amplifier ◽  
Ultra Wideband ◽  
Output Impedance ◽  
Integrated Inductor ◽  
Technology Process ◽  
Amplifier Design ◽  
Noise Amplifier

This paper presents the design of ultra-wideband low noise amplifier (UWB LNA). The proposed UWB LNA whose bandwidth extends from 2.5 GHz to 16 GHz is designed using a symmetric 3D RF integrated inductor. This UWB LNA has a gain of 11 ± 1.0 dB and a NF less than 3.3 dB. Good input and output impedance matching and good isolation are achieved over the operating frequency band. The proposed UWB LNA is driven from a 1.8 V supply. The UWB LNA is designed and simulated in standard TSMC 0.18 µm CMOS technology process.

scholarly journals A Broadband Ultrathin Nonlinear Switching Metamaterial

2017 ◽  
Vol 6 (2) ◽  
pp. 64
Author(s):  
E. Zarnousheh Farahani ◽  
S. Jarchi ◽  
A. Keshtkar
Keyword(s):  
Incident Wave ◽  
Optimization Method ◽  
Resonant Mode ◽  
Unit Cell ◽  
Incident Power ◽  
Full Wave ◽  
Effective Impedance ◽  
Nonlinear Simulations ◽  
Switching Property ◽  
Transmission And Reflection

In this paper, an ultrathin planar nonlinear metamaterial slab is designed and simulated. Nonlinearity is provided through placing diodes in each metamaterial unit cell. The diodes are auto-biased and activated by an incident wave. The proposed structure represents a broadband switching property between two transmission and reflection states depending on the intensity of the incident wave. High permittivity values are presented creating a near zero effective impedance at low power states, around the second resonant mode of the structure unit cell; as the result, the incident wave is reflected. Increasing the incident power to the level which can activate the loaded diodes in the structure results in elimination of the resonance and consequently a drop in the permittivity values near the permeability one as well as a switch to the transmission state. A full wave as well as a nonlinear simulations are performed. An optimization method based on weed colonization is applied to the unit cell of the metamaterial slab to achieve the maximum switching bandwidth. The structure represents a 24% switching bandwidth of a 10 dB reduction in the reflection coefficient.

scholarly journals Reconfigured and Notched Tapered Slot UWB Antenna for Cognitive Radio Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Tamer Aboufoul ◽  
Akram Alomainy ◽  
Clive Parini
Keyword(s):  
Cognitive Radio ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Total Efficiency ◽  
Back Side ◽  
Radiation Patterns ◽  
Uwb Antenna ◽  
Design Concepts ◽  
Specific Frequency

A compact reconfigurable and notched ultra-wideband (UWB) tapered slot antenna (TSA) is presented. The antenna reconfiguration operation principle relies on 2 mechanisms: in the first mechanism a resonator parasitic microstrip line electrically coupled to the TSA is used to notch the TSA at a specific frequency and the second mechanism relies on changing the input impedance matching of the antenna by means of changing the length of a stub line extended from an additional tiny partial ground on the back side of the antenna. The reflection coefficient, radiation patterns, and gain simulations and measurements for the proposed antenna are presented to verify the design concepts featuring a very satisfactory performance. Total efficiency simulations and measurements are also presented to highlight the filtering performance of the reconfigured antenna. When the antenna was reconfigured from the UWB to work into multiple frequency bands, the radiation patterns were still the same and the total peak gain has slightly improved compared to the UWB case. In addition, when the antenna operated in the notched mode, the gain has significantly dropped at the notch frequency. The simplicity and flexibility of the proposed multimode antenna make it a good candidate for future cognitive radio front ends.

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