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The Proceedings of the 2008 Antenna Applications Symposium is a collection of state-of-the art papers relating to antenna arrays, millimeter wave antennas, simulation, and measurement of antennas integrated antennas and antenna bandwidth and radiation improvements., Volume 1 of 2. Volume 2, AFRL-RY-HS-TR-2008-0026-Vol-2. Volume 1 contains pages 1-269. The original document contains color images. Presented at Proceedings of the Antenna Applications Symposium (32nd) held in Monticello, Illinois on 16-18 September 2008. See also ADA494633.

The Proceedings of the 2007 Antenna Applications Symposium is a collection of state-of-the art papers relating to antenna arrays millimeter wave antennas simulation and measurement of antennas integrated antennas and antenna bandwidth and radiation improvements., Volume 2 of 2. Volume 1, AFRL-RY-HS-TR-2008-0026-VOL-1. Volume 2 contains pages 270-524. The original document contains color images. Presented at Proceedings of the Antenna Applications Symposium (32nd) held in Monticello, Illinois on 16-18 September 2008. See also ADA494632.

This paper presents recent results describing the use of polyomino subarrays to introduce time delays into phased-array systems. Results for arrays of 8-element subarrays show suppression of peak quantization lobes to levels below -14 dB, relative to the quantization lobes of 8-element rectangular subarrays. Since algorithms for producing arbitrarily large arrays that tile rectangular areas are not available, we have combined smaller arrays chosen to be statistically independent. These have allowed the evaluation of ensemble averages of array gain, average and peak sidelobe levels., Published in the Proceedings of the 2006 Antenna Applications Symposium, p188-202, Sep 2006.

Phased array elements are often grouped into contiguous rectangular subarrays to reduce cost. This is done for two types of array applications. The first is for arrays that scan over only a limited sector, called limited field of view (LFOV) arrays. These use one phase shifter for each group of elements (subarray), and no phase shifters within the subarray. The second application is for arrays that scan over wide angles and wide frequency bands using time delay at the input to each subarray, and phase shift at every element. Unfortunately, contiguous rectangular subarrays used in these applications have substantial quantization lobes that limit their use to systems without strict sidelobe control. Figure 1 illustrates the use of contiguous rectangular subarrays for the LFOV and time delay applications. In these examples, a microstrip patch array is divided into subarrays that are four elements wide in the x direction, and two elements wide in the y direction. In Figure 1A, the limited field of view example, there are no phase shifters at the elements, and one phase shifter at each of the subarray input ports. This means that the subarray acts like a large element. The configuration shown achieves an 8:1 savings of phase shifters, but suffers reduced gain when the array is scanned. However, since the intention is to scan the array only through a restricted sector, then the reduced pattern gain can be tolerable., Presented at the Antenna Applications Symposium 2005, held in Monticello, IL., on 21 Sep 2005. Published in the Proceedings of the Antenna Applications Symposium 2005.