Grating lobe suppression in phased arrays composed of identical or similar subarrays
The grating lobe suppression methods for non-equidistant array antennas composed of identical or similar subarrays are proposed. Subarrays have equidistant rectangular or triangular grid. The grating lobes of an antenna array are reduced due to the irregular arrangement of subarrays. The following methods are considered: relative shift of neighbor subarrays, arranging gaps between subarrays, using different element spacing in different subarrays, rotation of subarrays, and combination of these methods. The methods provide suppression of the grating lobes from −2.6 dB to −11 dB as compared to equidistant arrays while side lobes envelop grows slightly.
A signal processing method to eliminate grating lobes
A signal processing method to eliminate grating lobes in case of array antenna is proposed in this paper. The proposed method of eliminating the grating lobes can be used in the cases where each antenna element information/data is available. By using the proposed method, relation between λ and baseline separation between the two antenna elements need not be less than or equal to λ/2. The proposed method eliminates the Grating lobes without hardware complexity with little processing load. It also reduces the antenna elements giving the same antenna pattern. Gain of the antenna patterns decides the number and the spacing between the antenna elements in the antenna array.
High gain antenna systems for millimeter wave radars with combined electronical and mechanical beam steering
Antenna systems for millimeter waves (MMW), considered in this paper, are large plane phased array antennas, installed on two axis angular positioners. This combination provides mechanical scanning in the upper hemisphere along with electronical scanning in a given conical scan sector. The modular (subarray) structure is the basis of designing the arrays described. The array architecture and achievable performances are discussed. Key elements developed for Ka-band arrays are presented.