In this paper, a new Wilkinson Power Divider ‎‎(WPD) using open and short stubs is proposed. ‎Open and short stubs are utilized instead of 1/4 wave transmission lines in initial ‎structure to achieve harmonics suppression. The proposed WPD is designed for ‎operational frequency of 0.9 GHz and creates 3 transmission ‎zeros at 1.8 GHz, 2.7 GHz and 3.6 GHz, for suppressing second, third and fourth harmonics. The proposed WPD has been fabricated and the ‎measurement results are in good accordance with simulation results. The designed ‎WPD has a 22 % fractional bandwidth with 0.1 dB insertion loss.‎

An ultra-wideband (UWB) bandpass filter with ultra-wide stopband based on a rectangular ring resonator is presented. The filter is designed for the operational frequency band from 4.10 GHz to 10.80 GHz with an ultra-wide stopband from 11.23 GHz to 40 GHz. The even and odd equivalent circuits are used to achieve a suitable analysis of the proposed filter performance. To verify the design and analysis, the proposed bandpass filter is simulated using full-wave EM simulator Advanced Design System and fabricated on a 20mil thick Rogers_RO4003 substrate with relative permittivity of 3.38 and a loss tangent of 0.0021. The proposed filter behavior is investigated and simulation results are in good agreement with measurement results.

In this article, a compact microstrip lowpass filter (LPF) using elliptical shaped resonators with ultra-wide stopband is rendered. In this respect, LC equal structures of the elliptical shaped resonators are calculated based on the formula of circumference. In addition, to calculate transmission zeros of the presented elliptical shaped resonator, the LC equal structure and its output to input ratio are employed. The proposed LPF has a −3 dB cut-off frequency at 1.50 GHz and the stopband bandwidth of the designed filter is about 13 f c, which refers to its ultra-wide stopband. The occupied circuit size of the presented filter is 0.151 λ _g × 0.044 λ _g ( λ _g is the guided wavelength at 1.50 GHz). The designed filter is fabricated on RT/Duroid 5880 substrate. The results of the fabricated and designed filter have clearly demonstrated that not only has the proposed LPF shown a suitable agreement between measured and simulated S -parameters, but also an appropriate stopband bandwidth.

A new microstrip lowpass filter with sharp roll-off and high suppression level in stop-band is presented. To achieve the lowpass filter with high performance, coupled T-shaped, elliptical and radial resonators are adopted. New formulas for calculating

Printed electronics (PE) present a promising alternative to conventional photolithography by enabling rapid prototyping with reduced costs, material waste, and enhanced design flexibility and advantages, particularly relevant for high-frequency microwave applications. This study presents the design, fabrication, and evaluation of two microstrip low-pass filters (LPFs) with cutoff frequencies of 2.60 GHz and 3.55 GHz serving as representative components for microwave circuits, using three additive manufacturing techniques: Direct-Write (DW), Screen Printing (SP), and Aerosol Jet Printing (AJP). Over 60 filter samples were fabricated and measured to systematically assess performance across different printing methods. The LPFs were designed and analyzed through electromagnetic simulations, complemented by an LC equivalent circuit model based on actual device dimensions to better understand their behavior. Measured frequency responses showed strong agreement with simulations, validating the effectiveness of all three printing methods. Each technique demonstrated unique trade-offs between resolution, fabrication complexity, and electrical performance, emphasizing the need to tailor method selection to specific application requirements. This paper offers valuable insights into the design, analysis, and fabrication of RF and microwave circuits using printed electronics, highlighting the strengths and limitations of each technique. It serves as a practical guide for researchers in selecting suitable methods for high-frequency applications.

In this paper, a new method with possible challenges for the development of microstrip resonators using Printed Electronics (PE) methods as an alternative technology to fabricate Radio Frequency (RF) circuits is presented. To validate the utilization of PE technology, two microstrip resonators were designed and simulated. Designed resonators are then realized with a dispensing (or so-called direct-write) printing system on a DuPont Teijin flexible polyethylene terephthalate (PET) foil with a thickness of 175 $\mu$m and a dielectric constatnt of 3. Simulated and measured frequency responses are compared, the process of printing microstrip structures is examined and results are discussed.