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This paper presents a substrate integrated waveguide (SIW) Chebyshev bandpass filter using the low cost, commercially available printed circuit board (PCB) technology. The detailed design procedure beginning from the normalized Chebyshev lowpass filter, to the final optimized SIW bandpass filter is presented. The test filter having a 4% fractional...
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A dual-layer 3-dB substrate-integrated waveguide power divider/combiner is designed, fabricated, and tested. Very good input and output matching as well as high isolation are exhibited over a measured 50% fractional bandwidth when a 10-dB reference level is considered. A completely shielded design significantly reduces insertion losses when compare...
A novel substrate integrated waveguide (SIW) 3 dB directional coupler based on air-filled vias (AFVs) is proposed and experimentally validated at Ka band. The AFV units can be used for tuning the effective permittivity by adjusting the dimensions of vias and period. Two rows of optimised AFVs are inserted in each branch of SIW directional coupler t...
Citations
... Deslandes et al. [2] introduced novel ideas for the comprehensive integration of planar circuits and waveguide filters produced on a single substrate using metallized post arrays (or via-holes). Augustine et al. [3] described a substrate-integrated waveguide (SIW) Chebyshev bandpass filter built with low-cost, commercially available printed circuit board (PCB) technology. Venanzoni et al. [4] offered an overview of substrate integrated waveguide (SIW) components designed for usage in X-band beamforming arrays. ...
Modern 5G telecommunications systems tend to use higher frequencies. The design of such devices is becoming increasingly miniaturized for more powerful applications and technologies. In this context, Substrate Integrated Waveguides (SIW) replace conventional waveguides. Their design is mainly based on mathematical models. However, the resulting model presents a frequency shift with respect to the working frequency. In this paper we present an optimization method for ensuring the good performance of waveguides, based on SIW technology. These waveguides are easily integrated into 5G telecommunication systems. We'll then look at the different results obtained after changing the variables asiw and h). The direct waveguide had the lowest frequency shift (|Δf|=0.11GHz) at asiw =3.6mm, whereas the indirect waveguide had the best frequency shift (|Δf|=0.01GHz) at asiw =3.25mm.
... With the increasing demand for wireless communication in our society today, communication systems have become more and more complex. As a result, filter requirements also becoming increasingly demanding which resulted in very complex filter structures [1]- [5] with very sophisticated filter function. ...
The aim of this paper is to show how coupling coefficients or coupling matrix of advanced filter response can be realized using microwave circuit simulators. Normally, an optimization or synthesis algorithm is used to determine such coupling matrix. Here, we present a procedure on how one can achieve the same using the available optimizer algorithm within commercial circuit simulators. A 6-order filter will be presented as an example. However, this technique is applicable to any number of poles. We will show how by merely using Chebyshev filter coupling coefficients as the starting point of the optimization process, the coupling coefficients of more advanced filter response can be determined. An electromagnetic simulated microstrip tri-band band-pass filter achieved using this procedure will be presented as an illustration.
... The RF band falls somewhere beneath the microwave range, though the border in the middle of the radio frequency and microwave bands is subjective and changes based on the method established for developing the band [2]. SIW transmission line [3][4][5][6][7][8][9][10] is basically a dielectric-filled waveguide implemented by two lines of conducting posts (also known as vias) implanted within a dielectric substrate, and electrically connecting the top and the bottom conducting walls [11]. The structural evolution of the SIW technology is shown in Figure 1 [3]. ...
... Microstrip to substrate-integrated waveguide conversions within multiple layered substrates were researched/reported [24]. Nwajana, Yeo, and Dainkeh proposed a new microstrip-CPW-SIW transition in [10]. The new transition technique exploits the step impedance on a 50Ω microstrip signal path, to the small impedance grounded coplanar waveguide, then linking to the SIW component through the brief small impedance grounded coplanar waveguide signal path. ...
Substrate-integrated waveguide (SIW) is a modern day (21st century) transmission line that has recently been developed. This technology has introduced new possibilities to the design of efficient circuits and components operating in the radio frequency (RF) and microwave frequency spectrum. Microstrip components are very good for low frequency applications but are ineffective at extreme frequencies, and involve rigorous fabrication concessions in the implementation of RF, microwave, and millimeter-wave components. This is due to wavelengths being short at higher frequencies. Waveguide devices, on the other hand, are ideal for higher frequency systems, but are very costly, hard to fabricate, and challenging to integrate with planar components in the neighborhood. SIW connects the gap that existed between conventional air-filled rectangular waveguide and planar transmission line technologies including the microstrip. This study explores the current advance-ments and new opportunities in SIW implementation of RF and microwave devices including filters, multiplexers (diplexers and triplexers), power dividers/combiners, antennas, and sensors for modern communication systems.
... The prototype diplexer circuit model is developed from two distinctly designed channel filters and a T-junction as shown in Fig. 2. The channel filters are designed using the procedure reported in [13], [14] with center frequencies that match to those of the Tx and the Rx channels of the proposed prototype microwave diplexer. The channel filters are designed to have a fractional bandwidth (FBW) of 0.03; a channel return loss of 20 dB; and a characteristics impedance of 50 Ohms. ...
A new formulation for implementing T-junction matching networks used in diplexer design is proposed in this paper. The investigation exploits the electrical length of quarter-wavelength microstrip transmission lines, and the guided-wavelength of the lines at one giga-Hertz frequency, in achieving the T-junction design formulation. This novel design would eradicate the uncertainties associated with frequent tuning and optimisation of T-junctions to achieve the desired energy distribution in diplexer designs. A prototype diplexer for separating the transmit from the receive frequencies within the front end of a wireless cellular base station is investigated and used to demonstrate the new design method. The prototype microwave diplexer with Tx and Rx centre frequencies of 2680 MHz and 3000 MHz, respectively, have been designed, implemented using microstrip, simulated, and presented. The simulation results of the circuit model and that of the microstrip layout prototype diplexer, demonstrate decent agreement with a high isolation of better than 50 dB between the transmit (Tx) and the receive (Rx) channels. The in-band lowest insertion loss is located at 1.1 dB, with a better than 20 dB in-band return loss across both the Tx and Rx bands.
... The proposed integrated FPS was formed using two separate, but identical three-pole channel filters designed following the technique reported in [15]. The design specification for the channel filters are as follows: Center frequency f0, 2.6 GHz; fractional bandwidth FBW, 3% and passband return loss of 20 dB. Figure 1 are the second and third resonators of the first and second channel filters, respectively. ...
... Z0 is the 50 Ohms characteristic impedance of each termination. The values for the J-inverters (i.e., J01 & J23), the capacitor C, and the inductor L were all calculated from [15] using Equations (1) and (2). The main contribution of this paper lies on the formulation for calculating the values of the J-inverters, J1 and J2 shown in Figure 1 using Equation (3). ...
... Each port represents a 50 Ohms termination. The values for k23 and Qext in Figure 4a were all calculated from [15] using Equation (4), where f1 and f2 are the eigenmodes from simulating a pair of microstrip resonators. The calculated values for k1 and k2 were determined using Equation (5). ...
A compact unbalanced two-way filtering power splitter with an integrated Chebyshev filtering function is presented. The design is purely based on formulations, thereby eliminating the constant need for developing complex optimization algorithms and tuning, to deliver the desired amount of power at each of the two output ports. To achieve miniaturization, a common square open-loop resonator (SOLR) is used to distribute energy between the two integrated channel filters. In addition to distributing energy, the common resonator also contributes one pole to each integrated channel filter, hence, reducing the number of individual resonating elements used in achieving the integrated filtering power splitter (FPS). To demonstrate the proposed design technique, a prototype FPS centered at 2.6 GHz with a 3 dB fractional bandwidth of 3% is designed and simulated. The circuit model and layout results show good performances of high selectivity, less than 1.7 dB insertion loss, and better than 16 dB in-band return loss. The common microstrip SOLR and the microstrip hairpin resonators used in implementing the proposed integrated FPS ensures that an overall compact size of 0.34 λg × 0.11 λg was achieved, where λg is the guided-wavelength of the 50 Ω microstrip line at the fundamental resonant frequency of the FPS passband.
... Hence, care must be taken when selecting design specifications to meet the most critical design targets. Some popular manufacturing techniques that have been employed in fabricating filters include printed circuit board (PCB) [21], low temperature co-fired ceramic (LTCC) [22] and liquid crystal polymer (LCP) [23]. In terms of low cost and commercial availability, the PCB wins and hence, has been utilized in the fabrication of the BPF reported in this paper. ...
... The BPF circuit model was established from the standard normalized 3-pole Chebyshev lowpass prototype filter shown in Figure 2 [21], where g is the filter parameter. The proposed BPF is designed to have a center frequency, f 0 of 2.6 GHz, a fractional bandwidth of 3%, a passband ripple of 0.04321 dB, and a passband return loss of 20 dB. ...
This paper presents a step-by-step approach to the design of bandpass/channel filters. A 3-pole Chebyshev bandpass filter (BPF) with centre frequency of 2.6 GHz, fractional bandwidth of 3%, passband ripple of 0.04321 dB and return loss of 20 dB has been designed, implemented, and simulated. The designed filter implementation is based on the Rogers RT/Duroid 6010LM substrate with a 10.7 dielectric constant and 1.27 mm thickness. The BPF was also fabricated using the same substrate material used for the design simulation. The circuit model and microstrip layout results of the BPF are presented and show good agreement. The microstrip layout simulation results show that a less than 1.8 dB minimum insertion loss and a greater than 25 dB in-band return loss were achieved. The overall device size of the BPF is 18.0 mm by 10.7 mm, which is equivalent to 0.16λg x 0.09λg, where λg is the guided wavelength of the 50 Ohm microstrip line at the filter centre frequency.
... The diplexer circuit model is formed from two separately designed channel filters and a Tjunction as shown in Fig.3. The two channel filters are designed using the technique reported in [20], [21] with centre frequencies that correspond to those of the Tx and the Rx bands of the proposed diplexer. Each filter is designed to have a fractional bandwidth of 0.03; a VOL.15, NO.6, NOVEMBER 2020 ...
A sixth order high isolation diplexer with Chebyshev channel filter characteristics is presented. The diplexer is proposed for isolating the transmit (Tx) and the receive (Rx) frequencies within the front end of a cellular base station. A novel formulation for achieving the T-junction used in distributing energy between the Tx and Rx channels is proposed. The formulation is based on the electrical length of transmission lines, and the guided-wavelength of the lines at one giga-Hertz frequency. The proposed formulation would help design engineers eliminate the uncertainties associated with repeated tuning and optimisation of T-junctions to achieve the desired energy distribution in diplexer designs. A test diplexer with Tx and Rx frequencies of 2.6 GHz and 3.0 GHz, respectively, have been designed, simulated, and presented. The design implementation is based on Rogers RT/Duroid 6010LM substrate with a 10.7 dielectric constant and 1.27 mm thickness. The circuit model and microstrip layout results of the diplexer show good agreement with a high isolation of better than 50 dB between the Tx and the Rx channels. The in-band minimum insertion loss is better than 1.1 dB, with a greater than 20 dB in-band return loss across both the Tx and the Rx bands.
... The proposed integrated FPD was formed using two separate but identical three-pole bandpass filters designed following the technique reported in [13], [14]. The design specification for the channel filters are as follows: centre frequency f0, 2.6 GHz; fractional bandwidth FBW, 3% and passband return loss of 20 dB. ...
... The idea did not change the effect of metallic walls, but gave rise to the SIW transmission line resonator/cavity. The SIW consists of two parallel rows of via holes embedded in the dielectric substrate as shown in Fig. 1 [16]; where w and l are the width the length of the SIW cavity, respectively, h is the thickness of the dielectric substrate, d is the diameter of the metallic post or via, and p is the pitch. Figure 1. ...
... Figure 1. Structure of the SIW cavity/resonator [16]. ...
A microwave diplexer implemented by using the twenty-first century substrate integrated waveguide (SIW) transmission line technology is presented. No separate junction (be it resonant or non-resonant) was used in achieving the diplexer, as the use of an external junction for energy distribution in a diplexer normally increases design complexity and lead to a bulky device. The design also featured a novel input/output coupling technique at the transmit and the receive sides of the diplexer. The proposed SIW diplexer has been simulated using the full-wave finite element method (FEM), Keysight electromagnetic professional (EMPro) 3D simulator. The design has also been validated experimentally and results presented. Simulated and measured results show good agreement. The measured minimum insertion loss achieved on the transmit and the receive channels of the diplexer are 2.86 dB and 2.91 dB, respectively. The measured band isolation between the two channels is better than 50 dB.
