Clency Lee-Yow

Integrated approach for compact high performance reflector antenna feeds

Custom Microwave Inc (CMI), uses a manufacturing technique known as electroforming along with precision microwave design CAD tools to integrate various components of a feed thereby achieving significantly smaller envelopes than is possible when using other manufacturing techniques. This integrated approach eliminates split joints and minimizes flange joints by integrating several components into single piece making it ideal for ultra low Passive Inter-Modulation (PIM) application. This approach also allows for high RF performance and higher power handling capability. A number of high performance feeds that CMI has produced for space application are presented to demonstrate the benefits of this integrated approach.

A Novel Method for High-Power Thermal Vacuum Testing of Satellite Payloads Using Pickup Horns

This paper presents the development of a novel method for high-power thermal vacuum (TVAC) testing of satellite payloads using pickup horns (PUH). It describes the design, manufacture, and qualification results for a Ku-band pickup horn, followed by high-power thermal vacuum test results of a Ku-band satellite for fixed satellite service. Based on the successful demonstration of this method, a generic pickup horn (GPUH) - with improved performance over a large bandwidth, covering 7.0 GHz to 21.0 GHz - was developed for testing of X-band, Ku-band, and Ka-band satellite payloads. Detailed design and qualification aspects of the generic pickup horn are addressed, including measured results. This method has been successfully employed for high-power thermal vacuum testing of three different satellites at Lockheed Martin Commercial Space Systems (LMCSS), and is the planned testing method for all future payloads.

Pick-up horn for high power TVAC test of spacecraft payloads for communication satellites

This paper presents a novel method for high power thermal vacuum tests of spacecraft payloads using pick-up horns (PUH). The PUH method has benefits of being cost-effective, compact, easy to implement, does not require breaking the vacuum several times and avoids physical contact with flight hardware. It is designed with four oversized slots to receive the high RF power from the flight horns, absorb almost all the power and efficiently transfer the heat outside the TVAC chamber with minimal reflections back to the horn and minimal RF leakage outside the PUH. The PUH has been successfully used for high power TVAC testing and validation of a Ku-band payload for satellite communications

Compact High-Performance Reflector-Antenna Feeds and Feed Networks for Space Applications [Antenna Applications]

Reflector antennas are widely used on satellites to communicate with ground stations. They simultaneously transmit and receive RF signals using separate downlink and uplink frequency bands. These antennas require compact and high-performance feed assemblies with small size, low mass, low passive intermodulation (PIM) products [1], low insertion loss, high power handling, and low cross-polar levels. The feeds must also be insensitive to large thermal variations, and must survive the launch environment. In order to achieve these desirable features without prototyping and/or bench tuning, Custom Microwave Inc. (CMI) has combined integrated RF design, precision CAD, and a precision manufacturing technique known as electroforming to closely integrate the various components of a feed or feed network, thereby achieving small size while maintaining high RF performance [2]. In addition to close integration, electroforming eliminates split joints and minimizes flanges by allowing several components to be realized in a single piece, making it the ideal manufacturing technique for ultra-low passive-intermodulation applications. This paper describes the use of precision design CAD tools along with electroforming to realize high-performance feed assemblies for various communication frequency bands for fixed satellite, broadcast satellite, and broadband satellite services.

A generic pick-up horn for high power thermal vacuum test of X, Ku, and Ka band satellite payloads

This paper presents development results of a generic pick-up horn (GPUH) for high power thermal vacuum (TVAC) test of satellite communications payloads. The GPUH is an improved method than the PUH that was presented earlier. It has much wider bandwidth of more than three octaves covering X-band, Ku-band, and Ka-band, can handle more power than the PUH, has better return loss, and is insensitive to polarization. Design and measured results of the GPUH are given here and are also discussed in an earlier publication.