Double Ridged Guide Horn Antenna Research Articles

Wideband 0.5–50 GHz double‐ridged guide horn antenna using coaxial‐to‐ridge waveguide launcher

AbstractEver‐increasing bandwidth requirements from various industries drive the need for the ever‐increasing bandwidth of antennas used for testing. Broadband Double‐Ridged Guide Horn (DRGH) antennas are used extensively in antenna measurement and ElectroMagnetic Compatibility/Interference (EMC/I) testing. The current state‐of‐the‐art broadband DRGH antennas reported in the literature for use in measurement applications cover bandwidth ratios as large as 36:1 (0.5–18 GHz). This paper presents the design and realisation of a DRGH antenna with a 100:1 bandwidth ratio (0.5–50 GHz). To achieve such a wide bandwidth, the ridge gap, width and feed were optimised, and a novel coaxial‐to‐ridge waveguide launcher section based on a typical Vivaldi antenna was developed. Backward radiation was reduced using an absorber‐filled cavity. A prototype DRGH antenna was manufactured using additive manufacturing, also referred to as 3D printing. Simulated and measured results obtained in an anechoic chamber are presented.

The Measurement of Complex Antenna Transfer Functions for Ultra-Wideband Antennas in a Compact Range [Measurements Corner

Ultra-wideband (UWB) communications technology increasingly plays an important role in modern communications systems. The complex antenna transfer function (CATF) of a UWB antenna provides valuable information that can be used for better UWB channel and communication system designs. Currently, only the two-antenna and three-antenna measurement techniques are used to measure the transfer functions and impulse responses of UWB antennas. In this paper, a modified version of the gain-transfer method is presented to enable the characterization of UWB antennas using a compact antenna test range facility (CATR). A double-ridged guide horn (DRGH) antenna was used as a UWB transfer-standard, and the complex antenna transfer function of the transfer-standard was determined a priori using full-wave simulations. The gain-transfer method to measure the complex antenna transfer function of UWB antennas in a compact antenna test range was illustrated with two test cases. In the first test case, the measured complex antenna transfer function of an ETS-Lindgren double-ridged guide horn antenna was verified with numerical data from a FEKO model of the antenna. The second case compared the complex antenna transfer function of a UWB circular disc monopole antenna measured in a compact antenna test range to measured data using two identical antennas in a two-antenna measurement setup.

An Improved Design for a 1–18 GHz Double-Ridged Guide Horn Antenna

It is a well known fact that the traditional 1-18 GHz double ridge guide horn (DRGH) antenna suffers from pattern deterioration above 12 GHz. At these frequencies, instead of maintaining a single main lobe radiation pattern, the pattern splits up into four lobes. It was shown in the literature that higher order modes are causing the pattern breakup. A benchmark study is performed to establish the performance of typical current and historic 1-18 GHz DRGH antennas. The performance of the antennas are evaluated in terms of gain, VSWR and radiation patterns. An improved 1-18 GHz DRGH antenna is presented. The new design has better gain and VSWR performance without any pattern deterioration. It also consists of significantly fewer parts, reducing the possibility of performance deterioration due to gaps between parts. Two prototypes of the new design were manufactured and tested with excellent agreement between measured and simulated results. The aperture dimensions of the new design are identical to that of the traditional DRGH, making it the only 1-18 GHz DRGH without pattern breakup whose aperture dimensions comply with the requirements specified in MIL-STD-461F - 24.2 by 13.6 cm.

Development of three-antenna method measurement system for low-sensitivity optical electric field sensor

A high-power three-antenna measurement system is successfully developed for calibrating the complex antenna factor of low-sensitivity sensors. First, the system is compared with a conventional three-antenna measurement system using double-ridged guide horn antennas, and the validity of the high-power system is confirmed. Then, the low-sensitivity optical electric field sensor is calibrated by this system and this result is compared with the standard field method. A good agreement between these results is obtained. The high-power three-antenna measurement system is therefore found effective for calibrating the complex antenna factor of low-sensitivity sensors.

Determination of gain of double-ridged guide horn antenna by considering phase center

The far-field gain of a double-ridged guide horn antenna is determined by the three-antenna method by considering the phase center. The location of the phase center is calculated by the finite integration method. The experimental and theoretical results show the efficacy of using the phase center for antenna calibration.

Design and Optimization of a New 1–18 GHz Double Ridged Guide Horn Antenna

A new design of a broadband 1–18 GHz double ridged guide horn antenna with redesigned feeding section is presented. Several modifications are made in the structure of a conventional double ridged guide horn antenna in order to overcome the deterioration of its radiation pattern at higher frequencies. Using the results of a sensitivity analysis of the most important parameters of the modified structure, it has been optimized by employing the interpolated quasi-Newton method. The resulting antenna not only does not suffer from the known deficiencies of a conventional antenna, but also has smaller physical dimensions and enjoys a better EM performance compared with the conventional one. The feeding section of this antenna is redesigned and the whole antenna has been optimized again to achieve a better VSWR. These modifications resulted in a VSWR of less than 2.7 at lower end of the frequency band and less than 1.8 at the upper end of the band. Reduction in the weight of the antenna and ease of construction are two other advantages of the new antenna.