scholarly journals Harmonic Suppressed Slot Antennas Using Rectangular/Circular Defected Ground Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Saeid Ghaffarian ◽  
Gholamreza Moradi ◽  
Reza Zaker
Keyword(s):  
Ground Plane ◽  
Reflection Coefficients ◽  
Harmonic Suppression ◽  
Radiation Patterns ◽  
Harmonic Frequency ◽  
Slot Antennas ◽  
Third Harmonic ◽  
The Third ◽  
Defected Ground Structures ◽  
Ground Structures

Two wide rectangle-shaped microstrip-fed 2.6-GHz slot antennas using defected ground structures (DGSs) with a low design complexity are proposed to achieve wideband harmonic suppression. To accomplish this, two rectangular DGSs (RDGSs) in the first antenna and two circular DGSs (CDGSs) in the second one with various dimensions are etched into the ground plane, which could have a wideband-stop characteristic. Simulated and measured reflection coefficients indicate that the two proposed structures effectively suppress the second and third harmonics up to 23 dB between 3.5 and 10.5 GHz with a maximum ripple of 2.4 dB. In addition, the radiation patterns and peak gains of the antennas can be suppressed at least 17 dB and 7.1 dBi, respectively, at the third harmonic frequency of 7.86 GHz.

Design and analysis of a planar UWB bandpass filter with stopband characteristics using MMR technique

2021 ◽  
pp. 1-8
Author(s):  
Gaurav Saxena ◽  
Priyanka Jain ◽  
Y. K. Awasthi
Keyword(s):  
Return Loss ◽  
Group Delay ◽  
Bandpass Filter ◽  
Ground Plane ◽  
Cost Effective ◽  
Ultra Wideband ◽  
Defected Ground Structures ◽  
Ground Structures ◽  
Multi Mode ◽  
Mode Resonator

Abstract In this paper, a ultra-wideband (UWB) bandpass filter with stopband characteristics is presented using a multi-mode resonator (MMR) technique. An MMR is formed by loading three dumbbell-shaped (Mickey and circular) shunt stubs placed in the center and two symmetrical locations from ports, respectively. Three circular and arrowhead defected ground structures on the ground plane are introduced to achieve UWB bandwidth with a better roll-off rate. The proposed filter exhibits stopband characteristics from 10.8 to 20 GHz with a 0.4 dB return loss. The group delay and roll-off rate of the designed filter are <0.30 ns in the passband and 16 dB/GHz at lower and higher cut-off frequencies, respectively. The dimension of the filter is 0.74λg × 0.67λg mm2 and was fabricated on a cost-effective substrate. All simulated results are verified through the experimental results.

scholarly journals A Triband Patch Antenna with Monopole-like and Patch-like Radiation Patterns for Multifunctional Wireless Systems

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hai-Na Song ◽  
Zhao-Hui Chen ◽  
Jian-Feng Li
Keyword(s):  
Radiation Pattern ◽  
Patch Antenna ◽  
Ground Plane ◽  
Wireless Systems ◽  
Metal Sheet ◽  
Radiation Patterns ◽  
Zeroth Order ◽  
Annular Slot ◽  
The Third

A triband patch antenna with monopole-like and patch-like radiation patterns for multifunctional wireless systems is proposed. The antenna consists of a single square radiation patch with an annular slot, a ground plane, and a top-loaded metal sheet. The top-loaded metal sheet is shorted to the ground plane for producing a zeroth-order resonant (ZOR) mode, which has an omnidirectional radiation pattern at the lowest operation band, and its performance is robust to the location of the probe feed. With the annular slot and the off-center probe feed, a dual-resonant TM01 mode is excited, yielding unidirectional radiation patterns for the two upper operation bands. The ZOR and the dual-resonant TM01 modes can be independently controlled, and a triband antenna prototype with a square patch of 24 mm is fabricated and tested. The first bandwidth is 2.5–2.7 GHz with omnidirectional radiation pattern, the second and the third bandwidths with unidirectional radiation are 3.3–3.9 GHz and 4.8–6.1 GHz, and the realized gains over the three bands are about 2.6, 6.5, and 7.5 dBi, respectively.

Triple band circularly polarized compact microstrip antenna with defected ground structure for wireless applications

2015 ◽  
Vol 8 (6) ◽  
pp. 943-953 ◽  
Author(s):  
Mukesh Kumar Khandelwal ◽  
Binod Kumar Kanaujia ◽  
Santanu Dwari ◽  
Sachin Kumar ◽  
Anil Kumar Gautam
Keyword(s):  
Circular Polarization ◽  
Ground Plane ◽  
Defected Ground Structure ◽  
Radiation Characteristics ◽  
Circularly Polarized ◽  
Left Hand ◽  
Right Hand ◽  
Defected Ground Structures ◽  
Ground Structures ◽  
Triple Band

Asymmetric slits loaded irregular shaped microstrip patch antenna with three different ground structures is proposed. All three antennas show triple band characteristics. First antenna with regular ground plane resonates at 1.95, 2.4, and 4.90 GHz with good radiation characteristics and shows right-hand circular polarization at 1.95 GHz. 18.75% of compactness is achieved with triple band characteristics. Further, same patch is used with different defected ground structures. Second antenna resonates at 1.85, 2.4, and 4.85 GHz with suppressed cross-polarization level and antenna shows right-hand circular polarization at 1.85 and 4.85 GHz. Compactness is further improved to the value of 22.91%. The third antenna resonates at 1.95, 2.4, and 4.85 GHz with better gain and radiation characteristics and antenna shows right-hand circular polarization at 1.95 and 2.4 GHz. The small frequency ratio f2/f1 is achieved and the value of f2/f1 is 1.29 and 1.23 for second and third configuration, respectively. Proposed structures show right-hand circularly polarized with suppressed left-hand circularly polarized radiations and suitable for fixed mobile wireless communication applications. All structures are analyzed using Ansoft HFSS v.14 based on finite element method and measured results satisfy the simulated results.

scholarly journals Composite Lowpass Filter Realized by Image Parameter method and Integrated with Defected Ground Structures

2018 ◽  
Vol 4 (2) ◽  
pp. 583-591
Author(s):  
Chandan Kumar Ghosh ◽  
Arabinda Roy ◽  
Susanta Kumar Parui
Keyword(s):  
Impedance Matching ◽  
Ground Plane ◽  
Cutoff Frequency ◽  
Parameter Method ◽  
Lowpass Filter ◽  
Microstrip Technology ◽  
Rectangular Slot ◽  
Lc Equivalent Circuit ◽  
Defected Ground Structures ◽  
Ground Structures

An asymmetric DGS consisting of two square headed slots connected transversely with a rectangular slot is etched in the ground plane underneath a high-low impedance microstrip line.  It provides a band-reject filtering characteristics with sharp transition. Thus, it may be modeled as m-derived filter section. Accordingly, T-type LC equivalent circuit is proposed and LC parameters are extracted. A planar composite lowpass filter is designed by image parameter method and implemented by different DGS units. A composite filter requires at least three filter sections, of which two m-derived sections and one constant k-section. In proposed scheme, one such m-derived section is directly replaced by proposed DGS unit, whose cut-off frequency is same as that of designed m-derived section. The other m-derived section implemented by proposed DGS unit divided into equivalent two L-sections which will act as a termination for impedance matching. A constant k-section has been realized by a dumbbell shaped DGS having same cutoff frequency. Here lumped LC parameters are directly replaced by the equivalent LC values of the DGSs and therefore, produce almost ideal filter characteristics by overcoming the limitations of microstrip technology.

scholarly journals Multiband Cross-Shaped Inverse Triangular Notch Antenna for Radio Shadow Zone Communication

2020 ◽  
Vol 20 (4) ◽  
pp. 320-326 ◽  
Author(s):  
Kyeong-Sik Min
Keyword(s):  
Mobile Communication ◽  
Ground Plane ◽  
Reflection Coefficients ◽  
Radiation Patterns ◽  
Shadow Zone ◽  
Communication Design ◽  
Triangular Structure ◽  
Measured Radiation ◽  
The Cross

This paper proposes a multiband cross-shaped inverse triangular notch antenna on a circular ground plane for a radio shadow zone mobile communication design for a broadband repeater antenna in the firefighting band for in-building mobile communication. To arrive at the broad and multi-bandwidth reflection coefficients, methods are considered for optimizing the cross-shaped notch antenna with an inverse triangular structure and the circular ground plane. The measured reflection coefficients are observed −10 dB lower in the firefighting band (440–450 MHz) and the mobile repeater band (890–2,450 MHz), and they agree well with those obtained through simulation. The desired omni-directional patterns are obtained in the firefighting band, even though the radiation patterns in the Wi-Fi band have directivity from 10° to 15° and from −10° to −50°. The measured radiation patterns and gains also agree well with the predictions.

scholarly journals Design of 0.8–2.7 GHz High Power Class-F Harmonic-Tuned Power Amplifier with Parasitic Compensation Circuit

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Zhiqun Cheng ◽  
Xuefei Xuan ◽  
Huajie Ke ◽  
Guohua Liu ◽  
Zhihua Dong ◽  
...  
Keyword(s):  
Power Amplifier ◽  
High Power ◽  
High Efficiency ◽  
Impedance Matching ◽  
Harmonic Suppression ◽  
Compensation Circuit ◽  
Third Harmonic ◽  
The Third ◽  
Saturated Output Power ◽  
Class F

The design, implementation, and measurements of a high efficiency and high power wideband GaN HEMT power amplifier are presented. Package parasitic effect is reduced significantly by a novel compensation circuit design to improve the accuracy of impedance matching. An improved structure is proposed based on the traditional Class-F structure with all even harmonics and the third harmonic effectively controlled, respectively. Also the stepped-impedance matching method is applied to the third harmonic control network, which has a positive effect on the expansion bandwidth. CGH40025F power transistor is utilized to build the power amplifier working at 0.8 to 2.7 GHz, with the measured saturated output power 20–50 W, drain efficiency 52%–76%, and gain level above 10 dB. The second and the third harmonic suppression levels are maintained at −16 to −36 dBc and −16 to −33 dBc, respectively. The simulation and the measurement results of the proposed power amplifier show good consistency.

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