This study denotes a procedure of a small phase noise (SPN) oscillator employing three different substrate integrated waveguide (SIW) resonators as a frequency stabilization‐component. The SIW resonator as modifying phase noise (PN) is investigated and branchline coupler in the feedback loop is presented. The design technique to attain SPN usage for optimized efficiency is proposed. Then, three different X‐band SIW oscillators using a packaged GaAs FET transistor are planned. Due to the PN and compacting, the miniaturized conventional SIW (MCSIW) oscillator is selected. This MCSIW oscillator operates at 8.15 GHz, mentions a PN of −169 dBc/Hz at 1‐MHz frequency‐offset.

Planar substrate integrated waveguide‐based resonators and its usage to compact X‐band small phase noise oscillator

In this paper, a novel compact planar coronavirus antenna is proposed for wide band applications. In the design of this antenna, the idea of the radiating part has been taken from the 3-D model of the coronavirus, which is fed by a 50 Ω coplanar waveguide. The patch structure and the feed line of the proposed antenna, which have been made of gold, are located on a polyamide substrate with a thickness and dielectric constant of 45 µm and 3.5, respectively, and the antenna has compact physical dimensions of 300 × 300 µm2. The simulation results of the antenna have been analyzed in terms of S11, VSWR, radiation pattern, gain and surface current distribution. The designed antenna covers the frequency band from 0.3627 to 0.5918 THz for S11 ≤ − 0 dB with a fractional bandwidth of > 47.98% and with a bandwidth ratio of 1.63:1. This extended bandwidth coverage allows the antenna to be suitable for a wide range of applications including wireless communications, internet of things, wearable devices, on-chip antennas and multiple-input multiple-output systems. Also, the results of the far-field show an omnidirectional radiation pattern with an average gain and efficiency of 4 dBi and 93% throughout the frequency band, respectively. 

/pdf/on-chip-coronavirus-shape-antenna-for-wide-band-applications-2qf53xrg.pdf

On-chip coronavirus shape antenna for wide band applications in terahertz band

A novel substrate integrated waveguide (SIW) adopting a leaky-wave antenna (LWA) for continuous beam scanning for tri bands is presented. For continuous beam scanning (CBS), optimization of different parameters associated with the unit cell has been carried out. Apart from this, optimal impedance matching is also obtained with the help of the characteristic impedance of the waveguide. The proposed SIW LWA scans from −58° to + 59° along with 14.50 dBi gain when the frequency changes from 10 GHz to 18.22 GHz and provides a scanning rate of 14.23. The beauty of the suggested antenna is its smaller size and high gain, along with a wider scanning range (117°) capability. This antenna’s final prototype has been fabricated, and the measurement results are matched with the simulation results.

/pdf/high-gain-and-wide-angle-continuous-beam-scanning-siw-leaky-1w6drzw9.pdf

High Gain and Wide-Angle Continuous Beam Scanning SIW Leaky-Wave Antenna

In this paper, a monopulse slot array antenna with substrate integrated waveguide (SIW) has been designed and fabricated for application in tracking systems. This antenna has circular polarization and has a very simple design. For increasing the efficiency of the antenna and maintaining its one-layer structure, this design utilizes two modes (TE120, TE210) to excite the slots rather than the complex feed network commonly used in monopulse antennas. The feeding ports are well-isolated due to the orthogonality of the two modes. The feeding cavity is operated in these two modes to obtain the difference and sum patterns. The proposed antenna at the center frequency of 10 GHz has an impedance bandwidth of 200 MHz, and the reflection coefficient in this bandwidth is less than −10 dB. The zero depth of the difference pattern is less than −24 dBi, while the obtained gain of the sum pattern is 13.6 dBi. The polarization axial ratio is less than 3 dB in the range of 9.98–10.02 GHz. Also, the antenna aperture efficiency is 50 % at the desired frequency. 

A monopulse array antenna based on SIW with circular polarization for using in tracking systems


 This article shows the design of two different low phase noise (LPN) planar X-band frequency oscillators using two various microstrip filters (MFs). These two MFs act as a frequency stabilization part in the loop of the microwave oscillator. The first one, the modified Jerusalem MF (MJ-MF), is based on the Jerusalem scheme. The second one, the complementary modified Jerusalem MF (CMJ-MF), is complementary of the MJ-MF. Finally, by employing the branchline coupler, the LPN MF oscillator is achieved. The MJ-MF (narrowband filter) LPN X-band oscillator operates at 8.17 GHz and denotes a phase noise (PN) of −161 dBc/Hz at 1-MHz frequency offset. The CMJ-MF (wideband filter) LPN X-band oscillator operates at 8.14 GHz and mentions a PN of −157 dBc/Hz at 1-MHz frequency offset.

A modified Jerusalem microstrip filter and its complementary for low phase noise X-band oscillator

In this paper, a leaky-wave antenna based on substrate integrated waveguide is introduced with continuous beam scanning from backward-to-forward through broadside. A new two-part unit cell has been used to achieve the continuous beam without drop of gain in the broadside. This suppresses the open stop-band, the broadside radiation gain would be without a drop, and the side lobe level is kept low. The wide operating bandwidth is obtained, which covers from 11.7 to 19.6 GHz. It is observed that S11 is below − 10 dB from 11.5 to 20 GHz, and the average S21 is − 8.5 dB from 11.5 to 20 GHz. Scanning of this antenna is continuous and covers all angles between − 61° to + 34°. The gain in the direction of the broadside beam is equal to 14.2 dB and without a drop. The gain changes are low in the operating frequency and the average gain is 14.1 dB in this antenna, also the average side lobe level is − 12 dB. The average radiation efficiency of this proposed antenna is 73%.

Pedram Sohrabi

Papers

A symmetrical SIW-based leaky-wave antenna with continuous beam scanning from backward-to-forward through broadside