Uros Jankovic

Ultra compact pseudo-elliptic inline waveguide bandpass filters using bypass coupling

This paper presents an ultra compact waveguide bandpass filter that exhibits a pseudo-elliptic response. The transmission zero created in the upper stopband to form a rapid roll off is produced through a bypass coupling with higher order modes. A 3rd order filter is designed at the centre frequency of 9.4 GHz with a 5.3% fractional bandwidth. The proposed structures size is 38% smaller than one of a 3rd order E-plane extracted pole filter with comparable response. Additionally, this configuration allows larger span of different bandwidths. The filter has been fabricated and tested using E-plane waveguide technology, which has benefits of being inexpensive and having mass producible capabilities. Measurements of such a fabricated filter validate the simulated results.

Electromagnetic modelling of dielectric-filled waveguide antenna filter arrays

This paper presents electromagnetic simulation of dielectric-filled rectangular waveguide antenna filter arrays. Arrays of microstrip rectangular patch antennas are endwall coupled with waveguide feeds that incorporate E-planes filters via slots in the ground plane. Signals can easily be distributed to/from these waveguides using microstrip technology, allowing antenna pattern synthesis and implementation of phased arrays. The key goals are compactness and good radiation characteristics. The antenna filter arrays are designed and simulated at the centre frequency of 11.85 GHz.

Stepped bend substrate integrated waveguide to rectangular waveguide transitions

A new wideband transition between substrate integrated waveguide (SIW) and rectangular waveguide (RWG) that resembles a right angle waveguide E-bend at Ku/K band is presented. The transition has removable but stable mounting, requires only PCB fabrication and has adaptable quality and bandwidth characteristics depending on the number of substrate layers used.

Compact inline e-plane waveguide resonators and bandpass filters with I-shaped resonant insets

In this paper, waveguide resonators and bandpass filters with E-plane inserts containing I-shaped resonant insets are presented. These insets introduce to the response finite transmission zeros much less sensitive than those produced by cross-couplings. Also, their use results in structure compactness, unlike bandstop resonant cavities that add volume. Two kinds of extracted pole sections that demonstrate response flexibility of the proposed resonators are designed at 10 GHz and tested. One is based on the dominant mode with a transmission zero in the upper stopband and the other on a pair of higher order modes with a transmission zero in the lower stopband. Also, a 3rd order filter for 11 GHz band combining both dominant and higher order mode resonators is modeled to illustrate the scalability of such a modular design. These filters are very suitable for low-cost mass production.

A magnetically biased graphene based CPW switch for microwave applications

This paper presents a coplanar waveguide (CPW) transmission line with added graphene patches in order to obtain switching properties. To toggle the switch state, magnetic biasing of graphene is used. The switch is simulated and results show that it can be operable at microwave frequencies.

Compact E-plane varactor -tuned bandpass filters

This paper presents electromagnetic simulation of a varactor-tuned E-plane waveguide band-pass filter. Silicon varactor diodes which can operate through X band are placed between gaps in the centre fins of an E-plane extracted pole section to provide tuneability for the filter structures. The simulation of the filter was carried out by CST Microwave Studio with the diodes being modelled by its Spice model in CST Design Studio. Tuning range of 280 MHz is achieved.