SYNTHESIS AND DESIGN OF MICROWAVE FILTERS FOR ADVANCED WIRELESS SYSTEMS

[Virtual Presenter] Today we will be discussing the synthesis and design of microwave filters for advanced wireless systems presented by Muhammad AbdulRehman, a Ph.D. Scholar in the Department of Electrical Engineering of Riphah University, with Supervisor Dr. Sohail Khalid. This presentation will cover how to improve microwave filter performance in terms of electrical performance, mechanical performance, and cost optimization..

[Audio] The slide provides an overview of the topic Synthesis and Design of Microwave Filters for Advanced Wireless Systems. This presentation will go into RF filter theory, provide a literature survey, and discuss design methodology. Results will be presented followed by a conclusion and future work section. Publications and references will also be included..

[image] Diagram schematic Description automatically generated.

Introduction. Department of Electrical Engineering.

[Audio] We will investigate the applications of microwaves, focusing on long distance communication, terrestrial communication, radar systems and defense applications. These technologies are utilized to enhance wireless systems through the utilization of microwave filters to build more efficient and sophisticated networks..

[Audio] In this slide, we'll discuss the fabrication techniques used for the synthesis and design of microwave filters for advanced wireless systems. These techniques include lumped components, waveguide, cavity, stripline, and microstrip configurations. Each of these configurations have their own benefits and drawbacks, and it is important to consider them before making a decision..

[Audio] In this slide, we will be discussing the performance measures that should be taken into account when designing microwave filters for advanced wireless systems. Good electrical performance can be achieved with low insertion loss, low reflection loss and flatness or ripple factor. We also need to ensure low group delay as well as higher selectivity and high out-of-band rejection. Finally, cost effectiveness should also be ensured..

Problem Statement. Department of Electrical Engineering.

[Audio] Today we will be discussing the synthesis and design of microwave filters for advanced wireless systems. Specifically, we will cover the problem statement, CAD technology, conventional analogue filters, performance measures, emerging technologies, regulatory compliance, complex design topologies, and literature survey findings. We will look at how using CAD technology, along with advances in engineering technologies, can help us create the best microwave filters for advanced wireless systems. Additionally, we will explore the performance measures, size, integration, frequency selectivity, power handling capability, cost-effectiveness, and regulatory compliance of these filters. Finally, we will assess the complex design topologies and literature survey findings that are applicable to our situation. With this information, we can determine the most effective synthesis and design of microwave filters for advanced wireless systems..

RF Filter Theory. Department of Electrical Engineering.

[Audio] RF filter theory has two main classifications: lowpass and high pass filter. A lowpass filter will pass frequencies below the cut off frequency while blocking frequencies above the cut off frequency. Conversely, a high pass filter will pass frequencies above the cut off frequency while blocking frequencies below the cut off frequency..

[Audio] Filters are an important component of modern wireless systems, and there are two main types used: Butterworth or Maximal Flat and Chebyshev or Equal Ripple Passband. Butterworth or Maximal Flat filters provide a fairly uniform frequency response throughout the filter response. Chebyshev or Equal Ripple Passband filters, on the other hand, are designed to allow a certain amount of pass band ripple. Both have their advantages and disadvantages, so the type of filter used should depend on what the application requires..

[Audio] Two-port networks are a fundamental element employed in the crafting of microwave filters. This slide will outline two of the parameters applied to characterize two-port networks, namely the Z-parameters and the Y-parameters. The Z-parameters are composed of three equations utilized to define the way signals pass through a two-port network, while the Y-parameters, another set of three equations, are employed to demonstrate the input and output impedances of the two-port network. Both sets of parameters can be utilized to design proficient microwave filters for more sophisticated wireless systems..

Transmission line. zo,ß zo,ß (b). Unit Element. RF Filter Theory.

Literature Review. Department of Electrical Engineering.

[Audio] We are looking at the table with research data regarding Ultra-Wideband (UWB) Bandpass Filters. It displays the number of the filter, the researcher, the frequency at which the filter is tuned, the number of transmission poles, and the Filter Bandwidth Percentage which is a measure of the filter's frequency response. Research has been conducted on eight different UWB Bandpass Filters, with different transmission poles and frequencies, to evaluate the performance of the filter in different wireless systems..

[Audio] This slide shows a table with data related to a Dual-band Bandpass Filter. This type of filter is widely used for wireless communications and is comprised of two passbands, designed to block frequencies outside of predetermined ranges. Studying the data allows us to evaluate the filter's performance. It is worth noting that the filter bandwidth or FBW can differ in accordance with the transmission poles and frequency ranges, which is demonstrated by the table..

[Audio] This slide focuses on the design of microwave filters for advanced wireless systems. A table lists designs made by different researchers and these designs are all Band Stop Filters with varying frequencies, transmission zeros and FBW (Fractional Bandwidth) percent ranging from 0.5 GHz to 2.5 GHz. It is evident that there is a lot of research done in this field and various variations of the bandwidths and transmission zeros for each design..

[Audio] We will be exploring the process of synthesizing and designing microwave filters for advanced wireless systems. This process involves analyzing conventional filter topologies, designing filter topology, ideal circuit simulation using Advanced Design System (ADS), optimizing the schematic design, full wave EM-simulation, and finally co-simulation optimization..

[Audio] The slide introduces a stub-loaded couple line ultra-wideband bandpass filter, intended for application in advanced wireless systems. It is formed by two low-pass and two high-pass filters, which together enable a wide passband. The design and analysis of the filter are further discussed..

Generalize Filtering Function UWB-BPF. Department of Electrical Engineering.

Synthesis of 4th Order UWB-BPF. A diagram of a diagram Description automatically generated.

[Audio] We can see from this slide that the table contains several parameters related to microwave filters. The fractional bandwidth, denoted as FBW, is the ratio of 3dB fractional bandwidth to the center frequency of the filter. The Return Loss is measured in decibels and reflects the minimum reflections of the filter. The parameters Z, Ze, and Zo refer to the filter input/output impedance. There is a positive correlation between FBW and Return Loss, whereby the wider the bandwidth, the higher the return loss. This is accounted for by the increased amount of signals amplified by the wider bandwidth. Conversely, the higher the FBW, the lower the resistance of the filter in terms of the input/output impedance..

A graph of a function Description automatically generated.

[Audio] A seventh order bandpass filter is a filter that is designed to pass a certain frequency range and block out undesired frequencies. It comprises of two or more poles that shape the passband response. The purpose of the design is to achieve greater attenuation of unwanted signals and reduced insertion loss in the desired frequency range..

Measured Results of Proposed 4th Order UWB-BPF. Department of Electrical Engineering.

Current Distribution of 4th Order UWB-BPF. A group of colored objects Description automatically generated with medium confidence.

[Audio] The slide shows the outcomes of the proposed 7th order ultra-wideband bandpass filter. Graphically represented are the simulated and measured S11, S21, and S12 with respect to a range of frequencies, displaying an attenuation of -60 dB and -100 dB respectively. These results were achieved by combining simulation and measured data, exemplifying successful synthesis and design of microwave filters for advanced wireless systems..

Current Distribution of 7th Order UWB-BPF. A rainbow colored lines on a white background Description automatically generated.

[Audio] The slide displays the group delay of a 7th order ultra wide band bandpass filter across the frequency range of 10 to 14 GHz. It has a maximum group delay of 2.5 nanoseconds and a minimum of -500 picoseconds, which are highly beneficial for modern wireless systems..

[Audio] In this slide we are looking at the comparison between the previously established studies and the proposed work. As you can see, the table provides us with the details of the complex filters which have been manufactured and researched by different sources. It also gives us a brief overview of the values reflected in each filter. This comparison allows us to evaluate the design specifications, frequency bandwidth, and other factors in each type of filter. This information will be utilized to compare and contrast the different approaches taken to create these filters and demonstrate which approach yields the best results..

[Audio] The slide focuses on the design of dual-wideband band-pass filters. The figure depicts the equivalent circuit model of the filter. The design topology of the filter has been initially presented and the next step is to adjust the filter in order to meet the requiered specifications..

Interdigital Capacitor (IDC). Department of Electrical Engineering.

[Audio] We will examine the relation between capacitance and physical parameters of interdigital capacitors, fundamental parts of microwave filters. We will investigate how the physical parameters of an interdigital capacitor can impact its capacitance and discuss strategies to use these elements for the optimization of wanted filter characteristics..

[Audio] The proposed model of an ideal dual band bandpass filter consists of two wideband bandpass filters, each providing a passband centered at a different frequency. This architecture allows two narrowband signals to pass through at the same time while providing excellent frequency selectivity. Figure 3.10 shows the model and it can be adjusted to meet the desired performance level..

Analysis of Proposed DB-BPF. A graph of a function Description automatically generated.

[Audio] A schematic model with independent values of impedance is presented in the slide for the analysis of the proposed DB-BPF. This filter is beneficial in advanced wireless systems for noise reduction and improvement of the signal-to-noise ratio, resulting in heightened accuracy and transmission range..

A graph of a passband and a passband Description automatically generated.

[Audio] A graph of a waveform is displayed, illustrating the concept of a filter. This filter is used to reduce the amount of unwanted signals in a wireless system. The waveform contains a series of peaks and valleys, each representing a different frequency of the signal. Through this graph, it is possible to understand how a filter works to reduce interference..

Layout Model of Proposed DB-BPF. A diagram of a machine Description automatically generated.

[Audio] The slide illustrates the distribution of the DB-BPF, or dual-band bandpass filter. It is a high pass filter at one frequency and a low pass filter at the other, thus offering versatility for utilization in a variety of wireless communication systems for better results..

[Audio] A diagram of a frequency spectrum is presented in this slide, which is significant for the synthesis and design of microwave filters for advanced wireless systems. The diagram demonstrates the frequency behavior, and can be used to design several varieties of filters, as well as to characterize the signal output of the filter..

[Audio] The proposed DB-BPF, or double balanced band-pass filter, was designed for advanced wireless systems. Its group delay is presented in the chart, demonstrating that the filter is able to support a wide range of RF applications that require either high-pass or low-pass filters, making it a more versatile option..

[Audio] We are analyzing a comparison between previously proposed DB-BPF (dual-band Band-Pass Filters) and the DB-BPFs proposed in this work. The table shows the Cutoff Frequencies (CFs) of the previous DB-BPFs in GHz, the number of transmission zeros (TZs) and the number of transmission poles (TPs). Additionally, the fractional bandwidth (FBW) is also given [in percentage]. The last row of the table covers the DB-BPFs proposed in this work, which have 8 GHz Cutoff Frequency, 7 TZs and 7 TPs. By looking at this table, we can compare and contrast the former designs with the newly proposed one. Furthermore, the proposed DB-BPF design shows a higher FBW than the previously proposed DB-BPFs..

[Audio] An analysis of how to design a wideband Bandstop Filter for advanced wireless systems is presented in this slide. This kind of filter is advantageous to eliminate interfering signals in certain frequency bands from a wide range of input frequencies. A cascaded ladder structure synthesis is employed to reduce the size and cost of the microwave filter. Simulation results have been provided to validate the accuracy of the proposed filter..

Comparison of S21 Magnitude. A graph of a number of numbers Description automatically generated.

[Audio] This slide demonstrates the simulated results of the proposed bandstop filter. The goal of the filter is to provide strong attenuation in the stop band, while preserving relatively low passband insertion loss. The graph clearly indicates that this filter meets the specifications of a bandstop filter and is suitable for use in advanced wireless systems..

Microstrip Design. UNrvAT70NAJ. Department of Electrical Engineering.

[Audio] We will be examining the results of the proposed BSF (Band Stop Filter). On the graph, the frequency is on the x-axis and the results of the proposed BSF on the y-axis. Simulated and measured values for -20, -40, -60, -100, -120, TPI, SII, S12, and TP2 are indicated. The results appear to be very good, showing that the filter is effective and dependable..

[Audio] A visual representation of the current distribution of a proposed band-stop filter (BSF) is seen in this slide. BSF is a type of microwave filter designed to stop signals within certain frequency bands. The filter has a symmetric current distribution with a null at its center, a feature that aids in reducing the filter size and improving signal quality. Thank you for listening to my presentation..