A Compact Size, High Isolation and Low Insertion Loss Microstrip Diplexer

2018 ◽  
Vol 27 (13) ◽  
pp. 1850211
Author(s):  
S. H. Esmaeli ◽  
S. H. Sedighy
Keyword(s):  
Insertion Loss ◽  
Fine Tuning ◽  
Coupled Line ◽  
High Isolation ◽  
Coupling Capacitance ◽  
Design Flexibility ◽  
Compact Size ◽  
Low Insertion Loss ◽  
Defected Ground Structures ◽  
Insertion Losses

A compact microstrip diplexer with low insertion loss and high isolation is proposed by combination of two coupled line bandpass filters (BPFs). An additional zero in the lower BPF transmission is created by a coupling capacitance which can be tuned at the higher channel and improve the isolation, consequently. Moreover, defected ground structures (DGSs) are used for more design flexibility and fine tuning of the structure. A diplexer prototype with two passbands at 1.24[Formula: see text]GHz and 1.5[Formula: see text]GHz is fabricated and tested. The measured insertion losses in the passbands are less than 1.2[Formula: see text]dB while the isolation between two channels is greater than 25[Formula: see text]dB and the input return losses of the three ports are about 20[Formula: see text]dB. These results in comparison with the references verify the good performance and ability of the designed duplexer.

Compact four-band diplexer using defected ground structures

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liang Li ◽  
Jianzhong Chen ◽  
Yuanbao Chen
Keyword(s):  
Insertion Loss ◽  
Group Delay ◽  
High Isolation ◽  
Compact Size ◽  
Physical Position ◽  
Low Insertion Loss ◽  
Defected Ground Structures ◽  
Ground Structures

Abstract In this paper, a novel four-band diplexer using defected ground structures with compact size, low insertion loss and high isolation is presented. To begin with, there are 16 defected ground stepped impedance resonators (DSIRs) controlling four passbands characteristics. Every four DSIRs can generate one passband. Then, four different DSIRs use the same feeding line. According to the group delay, we can determine the relative physical position of the first resonator. For the demonstration, a four-band diplexer operating at 2.45/4.2 and 3.5/5.2 GHz with the fractional bandwidths of 10, 7, 6.2 and 5% is designed and fabricated. Finally, measured results agree well with simulated results.

Miniaturized Wideband Bandpass Filter based on Capacitor-loaded One-eighth Wavelength Coupled Line

2021 ◽  
Vol 36 (7) ◽  
pp. 865-871
Author(s):  
Jin Shi ◽  
Jiancheng Dong ◽  
Kai Xu ◽  
Lingyan Zhang
Keyword(s):  
Insertion Loss ◽  
Simple Structure ◽  
Bandpass Filter ◽  
State Of The Art ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Coupled Line ◽  
Transmission Zeros ◽  
Compact Size ◽  
Multiple Transmission

A novel miniaturized wideband bandpass filter (BPF) using capacitor-loaded microstrip coupled line is proposed. The capacitors are loaded in parallel and series to the coupled line, which makes the filter just require one one-eighth wavelength coupled line and achieve filtering response with multiple transmission poles (TPs) and transmission zeros (TZs). Compared with the state-of-the-art microstrip wideband BPFs, the proposed filter has the advantages of compact size and simple structure. A prototype centered at 1.47 GHz with the 3-dB fractional bandwidth of 86.5% is demonstrated, which exhibits the compact size of 0.003λ2 g (λg is the guided wavelength at the center frequency) and the minimum insertion loss of 0.37 dB.

scholarly journals Design and simulation of low actuation voltage RF MEMS shunt capacitive switch with serpentine flexures&rectangular perforations

2018 ◽  
Vol 7 (2.31) ◽  
pp. 4 ◽  
Author(s):  
K Jayavardhani ◽  
S K. Noureen Fathima ◽  
K Bhima Sankar ◽  
K Kavya Sri ◽  
S Sunithamani
Keyword(s):  
Insertion Loss ◽  
Rf Mems ◽  
Actuation Voltage ◽  
Air Gap ◽  
Spring Constant ◽  
Squeeze Film ◽  
Capacitive Switch ◽  
High Isolation ◽  
Low Insertion Loss ◽  
Rf Performance

This paper presents the design and simulation of RF MEMS shunt capacitive switch with low actuation voltage, low insertion loss and high isolation. Actuation voltage depends on the parameters like air gap, spring constant and actuation area. In this design, we have proposed a serpentine meander structure to reduce the spring constant of the beam thus reducing actuation voltage. The rectangular perforation is used to reduce the squeeze film damping by decreasing the mass of the switch. The proposed switch has attained a low actuation voltage of 4.5V for a displacement of 0.84μm. The air gap between the beam and the dielectric is 1μm. This radio frequency (RF) MEMS shunt switch is designed and simulated using COMSOL Multiphysics 5.2. The RF performance of the shunt switch is analyzed in Ansoft HFSS 13 and the results show that the return loss was about -13.50 dB at 20GHz in the OFF state and -8.5 dB at 18 GHz in the ON state. A high isolation of -36.00 dB was achieved in the OFF state at a frequency of 5GHz and a low insertion loss is obtained. The results show that the switch is suitable for wireless applications operating in the frequency range from 5 to 20GHz. 

scholarly journals Reconfigurable Negative Group Delay Circuit with a Low Insertion Loss Using a Coupled Line

2020 ◽  
Vol 20 (1) ◽  
pp. 73-79
Author(s):  
Girdhari Chaudhary ◽  
Yongchae Jeong
Keyword(s):  
Insertion Loss ◽  
Group Delay ◽  
Characteristic Impedance ◽  
Center Frequency ◽  
Pin Diode ◽  
Negative Group ◽  
Coupled Line ◽  
Coupled Lines ◽  
Low Insertion Loss ◽  
Negative Group Delay

This paper presents a design of a transmissive-type, low insertion loss (IL) negative group delay (NGD) circuit with a reconfigurable NGD. The proposed circuit consists of a series transmission lines (TLs) and shunt short-circuited coupled lines where an isolation port is terminated with a parasitic compensated PIN diode. Analytical design equations are derived to obtain the circuit parameters for the predefined NGD and IL. The low IL can be achieved because of the very high characteristic impedance of the short-circuited coupled lines. The TL terminated with a PIN diode is used to achieve the constant center frequency of reconfigurable NGD circuit. For experimental validation, the NGD circuit is designed and fabricated at a center frequency (<i>f</i><sub>0</sub>) of 2.14 GHz. In the measurement, the NGD varies from -0.5 ns to -2 ns with an IL variation of 2.08 to 3.60 dB at <i>f</i><sub>0</sub> = 2.14 GHz. The NGD bandwidth (bandwidth of GD less than 0 ns) varies from 90 MHz to 50 MHz. The minimum input/output return losses are higher than 10 dB for the overall tuning range.

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