Design of a resonant edge-slot waveguide array for the Lightweight Rainfall Radiometer (LRR)

Abstract

Several X-band resonant edge-slot waveguide arrays were designed and fabricated for the passive X-band radiometer being flown on the NASA Lightweight Rainfall Radiometer (LRR) aircraft mission. The advantage of this antenna for aperture synthesis between adjacent linear arrays is described along with detailed description of a modern technique for designing resonant edge-slot waveguide arrays. What made this achievement most noteworthy was this historically difficult design was accomplished at very low cost without manufacturing any hardware prototypes and the antenna was very well-optimized. This paper will summarize the development effort, and present engineering design curves used to create this low-sidelobe antenna design and data measured from the radiometer antenna.

Optimum design of travelling rectangular waveguide edge slot array with non‐uniform spacing

“…To calculate the mutual impedance between the two slots, we first compute the mutual impedance between two dipoles using the Baker and LaGrone [13] method. Then, we obtain the expression for the mutual impedance between the two slots by the Babinet's principle (Z slot Z dipole = ((η 2 )/4)) and insert it in the error function.…”

“…The numbering of slots starts from the left at the array feed point. The resulting pattern as determined by (13) and HFSS are given in Fig. 4 for comparison.…”

“…The slot arrays on the narrow walls of rectangular waveguides have many applications in radar and communication systems, owing to their high gain and efficiency, mechanical strength and no spurious radiation from their feeding system [5][6][7][8][9][10][11][12]. The applications of such slot antenna are in radar systems, radiometer antenna (such as NASA lightweight rainfall radiometer (LRR) [13] and military aircraft (e.g. AWACS)).…”

Design of traveling wave slotted waveguide array antenna with high efficiency

“…One of the most important applications of edge aperture array antennas, or the so-called transverse tilted aperture antennas, is in radars, digital warfare, and communications, for its ease of manufacture and its distinction of low cost, high gain and little loss [12], [13]. On the other hand, it is equally difficult to analyze theoretically precisely because of the effects of its thick wall and the mutual coupling between its hole [14]- [16]. Nowadays, we notice that many applications of image sensing or in medical equipment and devices adopt focus in near fields to focus beams at a certain distance, which is called the focal distance of the antenna such as planar antennas, the slotted rectangular waveguide antennas, in addition to the dielectric lens antennas, but all of these antennas have a two-dimensional focus of radiation.…”

Edge slot waveguide array antenna for an omnidirectional radar system

“…This presents a considerable design challenge since the realized gain must be maintained at ~12 dBi. An edge slot waveguide array antenna [2][3][4] has been developed to meet these system requirements of high gain and minimized antenna depth.…”