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TABLE 6: PERFORMANCE OF FOUR-ELEMENT LINEAR ARRAY WITH AMPLITUDE TAPER Four-Element Linear Array Conductor Pattern (note power divider line impedance difference) Four-Element Linear Array Conductor Current 21 (note unequal amplitude and equal phase excitation) Four-Element Linear Array Radiation Patterns (note reduction to sidelobes versus equal amplitude) Four-Element Linear Array Input Impedance (note increase in impedance match bandwidth over single element) Table 7 illustrates the configuration of a two-x-two array. The two-x-two array excitation is generally uniform and the feature most prominent is that the gain is typically 6 dB above the single element configuration with the commensurate reduction in E-plane and H-plane beamwidth. In this case, the gain, 11.45 dB, is limited due to the inclusion of line and impedance mismatch loss. The conductor current discloses that each element of the array is uniformly excited in amplitude and phase. 21 The current density annotation feature available within the AXIEM EM analysis software provides significant physically insightful information. The graphic indicates that the amplitude and phase of the individual element excitation are equal. This feature is uniquely valuable in evaluation of proper amplitude and phase excitation of more complex array structures. 1 0 -10 -20 -30 -40 -50 -60 -70 -80 - 9 0 -100 -110 -120 -130 -140 -150 -160 -170 180 170 160 150 140 130 120 110 100 9 0 80 70 60 50 40 30 20 10 Azimuth and Elevation Patterns Mag Max 20 dB Mag Min -30 dB 10 dB Per Div p2 p1 Mag 11.63 Ang 0 DB(| PPC_EPhi(0,1,90,2,1)| )[3] 1_x_4_Array.$FSAMP DB(| PPC_ETheta(0,1,0,2,1)| )[3] 1_x_4_Array.$FSAMP p1: FREQ = 5.8 GHz p2: FREQ = 5.8 GHz 0 1.0 1.0 -1.0 10.0 10.0 -10.0 5.0 5.0 -5.0 2.0 2.0 -2.0 3.0 3.0 -3.0 4.0 4.0 -4.0 0.2 0.2 -0.2 0.4 0.4 -0.4 0.6 0.6 -0.6 0.8 0.8 -0.8 Input Impedance Swp Max 5.9GHz Swp Min 5.7GHz 5.8 GHz r 1.06272 x 0.0449938 S(1,1) 1_x_4_Array.$FSAMP Microstrip Antenna Design 18 www.cadence.com/go/awr

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