Design and fabrication of a compact microstrip triplexer for wimax and wireless applications

A novel structure to design a microstrip triplexer for wireless and WiMAX applications is presented. To obtain a compact microstrip layout, step impedance resonators and coupled lines are used. The introduced triplexer has a size of 0.35λg×0.26λg, where λg is calculated at 2.3 GHz. Also, the obtained insertion losses are 0.78 dB, 1.1 dB and 0.62 dB at 2.3 GHz, 3.2 GHz and 3.6 GHz, respectively. The LC model of the presented resonator is investigated to tune three resonance frequencies by calculating numerical values of inductors and capacitors. Finally, the designed triplexer is simulated and measured

Design of Multiplexers for IoT-Based Applications Using Stub-Loaded Coupled-Line Resonators

This paper presents the design of microstrip-based multiplexers using stub-loaded coupled-line resonators. The proposed multiplexers consist of a diplexer and a triplexer, meticulously engineered to operate at specific frequency bands relevant to IoT systems: 2.55 GHz, 3.94 GHz, and 5.75 GHz. To enhance isolation and selectivity between the two passband regions, the diplexer incorporates five transmission poles (TPs) within its design. Similarly, the triplexer filter employs seven transmission poles to attain the desired performance across all three passbands. A comprehensive comparison was conducted against previously reported designs, considering crucial parameters such as size, insertion loss, return loss, and isolation between the two frequency bands. The fabrication of the diplexer and triplexer was carried out on a compact Rogers Duroid 5880 substrate. The experimental results demonstrate an exceptional performance, with the diplexer exhibiting a low insertion loss of 0.3 dB at 2.55 GHz and 0.4 dB at 3.94 GHz. The triplexer exhibits an insertion loss of 0.3 dB at 2.55 GHz, 0.37 dB at 3.94 GHz, and 0.2 dB at 5.75 GHz. The measured performance of the fabricated diplexer and triplexer aligns well with the simulated results, validating their effectiveness in meeting the desired specifications.publishedVersio

A Review on the Structure, Application and Performance of the Passive Microstrip Devices

Microstrip technology is widely applied for design and implementation of several communication devices such as filters, diplexers, triplexers, multiplexers, couplers, etc. They are utilized to isolate desired signals and remove disturbing signals. The layout of filters, diplexers and triplexers have two, three and four ports, respectively. Passive filters have at least one pass channel, whereas diplexers have at least two channels to transmit the desired signal, and multiplexers have more passbands with more channels. In order to implement the passive components, first a cell called resonator must be designed. Creativity is very important in resonator design. It must be small and novel to get a better device than previous works. Therefore, the layout of previous reported resonator, used in passive microstrip devices, are studied in this work. There is a fierce competition among designers to miniaturize and increase the device performance. Hence we will investigate them, from the point of view size and performance, in this work. Some diplexers are multi-channel, which are more difficult to design than two-channel diplexers. Therefore, the multi-channel diplexers are less reported than the two-channel diplexers. The design of multiplexers is also very difficult because several channels must be controlled. Hence, they are less designed than filters and diplexers. The diplexers can be bandpass-bandpass or lowpass-bandpass, where the latest is less designed. This is because designing a lowpass-bandpass diplexer needs lowpass and bandpass resonators, whereas the design of a bandpass-bandpass diplexer needs only a bandpass resonator

High-Q Millimeter Wave RF Filters and Multiplexers

For a long period of time, millimeter waves (mm-Wave) were considered unsuitable for wireless data transmission due to high attention while propagating in the atmosphere. Over the past few years, due to the vigorous developments of multiple-in-multiple-out (MIMO) antenna technology and semiconductor technology, it is now feasible to have reliable wireless data transmissions using mm-Wave. Traditionally, mobile communication networks operate in the frequency spectrum under 6 GHz. In order to meet the ever-increasing demand for high communication data rate and high-quality multi-media services, the current fifth generation (5G) and the emerging 6G mobile communication systems will start to utilize the mm-Wave spectrum due to its bandwidth advantages, which in turn translates into a high data transmission rate. Millimeter-wave technology is also widely used in radar, imaging, medical therapy, and sensing applications. For those reasons, over the past few years, the interest in mm-Wave spectrum has significantly increased. RF filters are essential components in any communication systems to provide frequency selectivity. As the operating frequency of communication systems is extending to the mm-Wave spectrum, the conductor loss, the dielectric loss, and the radiation loss increase rapidly, which makes it challenging to develop high-Q mm-Wave filters. Three-dimensional (3D) waveguide filter structures exhibit excellent RF performance at mm-Wave frequencies and have been widely employed in high-performance RF systems. Nevertheless, as the operating frequency increases to mm-Wave frequency, the physical sizes of the waveguide filters become miniature in size impeding the use of post-fabricated tuning elements to compensate for the manufacturing tolerances of the traditional machining technologies. The silicon-micromachining technology has the potential to develop very accurate miniature 3D filters. This thesis focuses on the development of high-Q ultra-wideband mm-Wave planar filters using multilayer superconductor technology and 3D filter structures using silicon micromachining technology, making use of recent advances in deep reactive ions etching (DRIE) techniques. This thesis first introduces a new technique for filter design and tuning using the phase of the input impedance (PII) as the design parameter. This novel method is applicable to both narrow and wideband filters. Compared with conventional filter design and tuning methods, this approach requires less computation time and provides a clear step-by-step procedure for identifying the proper inter-resonator coupling and the resonant frequencies of the resonators. In practice, the physical realization of the filter always has a non-ideal I/O port, which can introduce an unexpected unknown transmission line between the physical reference plane and the port of the corresponding inverter in the circuit model. In this thesis, the PII response is used to determine the equivalent electrical length of this unknown transmission line. The validity of the proposed technique is demonstrated through the design of a wideband planar filter with a fractional bandwidth of 72%, the tuning of filters with transmission zeros and the design of a wideband diplexer. The multilayer superconductor technology allows to realize high-Q planar structures with highly miniature physical dimensions. The superconductor digital receivers can directly digitalize RF signals up to very high frequencies, eliminating the need to use mixers and oscillators to convert the RF signals to lower frequencies. This thesis demonstrates the feasibility of an ultra-wide band superconductor mm-Wave continuous triplexer that can be integrated with superconductor analog to digital converter (ADC) on a single niobium chip. A wideband high-Q mm-Wave highly miniature niobium-based superconductor multiplexer realized on an 8-layer niobium process has been developed, fabricated, and tested covering the frequency range 20 GHz - 80 GHz. In addition to monolithic integration of the superconductor multiplexer with the superconductor ADC, the thesis also demonstrates the feasibility of mounting the triplexer chip on a multi-chip-module (MCM) substrate using flip-chip technology interfaced with 1 mm mm-Wave connectors. This thesis also demonstrates using a unique behavior of spiral inductors designed intentionally to have a large parasitic capacitance in the realization of a tunable band reject filter. It is shown that, regardless of the operating frequency, the conductivity of the metal strips forming the inductor has a significant impact on how the spiral inductor behaves as an inductor or a capacitor. The concept is used to demonstrate a band reject filter made from a multilayer niobium circuit operating at 4 Kelvin. Such band reject filters are needed in the front-end of superconductor digital receivers to eliminate interference. Micromachining fabrication processes provide much higher manufacturing accuracy than traditional CNC machining technologies. Moreover, the DRIE silicon micromachining process is more economical for mass production and makes it possible to produce highly accurate 3D waveguide structures. This thesis presents filter designs composing of highly miniature silicon-micromachined ridge waveguide resonators. The proposed filter designs provide highly compact physical size with reasonable high Q values. An ultra-high-Q mm-Wave cavity filter employing a silicon-micromachined barrel-shape cavities operating in TE011 mode has been developed, fabricated and tested. The barrel-shape is proposed to realize a high-Q cavity, while circumventing the spurious issues of the degenerate TM modes that exist in traditional cylindrical-shape cavities. The filter was realized on silicon using DRIE techniques

Manifold Multiplexer

In wireless communications, bandwidth is a valuable resource that can be smartly shared by multiple users simultaneously utilizing multiplexers. This chapter offers a short review and brief impression of the working principle and the design methodology of the multiplexers in RF and microwave systems. Predominantly used different multiplexer design patterns are discussed here, however the compact manifold multiplexer is discussed in details with an example. It is designed by using advanced design system (ADS) software and implemented utilizing Microstrip technology for its low cost and simplicity

Hybrid Microstrip Diplexer Design for Multi-band WiMAX Application in 2.3 and 3.5 GHz Bands

In this paper, a design of hybrid microstrip diplexer is proposed for multi-band Worldwide Interoperability for Microwave Access (WiMAX) application in 2.3 and 3.5 GHz bands. The diplexer consists of a combination of two different filter designs. These filters were designed based on microstripline coupling techniques in order to obtain minimum insertion losses and achieve the desired frequency bandwidth. Therefore, a coupled open loop ring resonator was chosen for the filter design in 2.3 GHz band and a folded coupled line resonator was chosen for the filter design in 3.5 GHz band. Then, these filters were combined with a ring manifold matching network to be a hybrid microstrip diplexer. Based on the results, good agreements were achieved between the simulation and measurement results in terms of insertion loss, return loss and bandwidth in the 2.3 and 3.5 GHz bands

Shuttle orbiter S-band communications equipment design evaluation

An assessment of S-band communication equipment includes: (1) the review and analysis of the ability of the various subsystem avionic equipment designs to interface with, and operate on signals from/to adjoining equipment; (2) the performance peculiarities of the hardware against the overall specified system requirements; and (3) the evaluation of EMC EMI test results of the various equipment with respect to the possibility of mutual interferences