While most conventional airborne radars rely on some form of mechanically scanned antenna to transmit and receive signals, active electronically scanned array (AESA) sensors employ a fixed aperture.

当多数常规机载雷达依靠机械扫描天线收发信号的时候，有源电子扫描阵列(AESA)传感器却使用固定的孔径。

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The main lens is fixed in place; there is no auto-focus, auto-aperture, or other gubbins.

主要镜头是固定的，没有自动对焦和自动光圈以及其他小配件。

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Many formulae used to calculate fixed phase distribution for the array lens, configuration curve of the dielectric lens and aperture phase of a feed phased array are derived.

给出了计算阵列透镜配相、介质透镜外形曲线和平面相控阵天线孔径相位的若干计算公式。

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He left it on a fixed aperture, so that as the light faded, the exposure got ever longer.

BBC: Cameras to capture a road trip

In addition to daily use as a "pan-focus" lens featuring a wide angle, fixed f8 aperture and shallow depth of field, it is compatible with manual focusing using a lever and capable of close-up shooting as close as 30 cm.

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Inmarsat is also entering a new field, the fixed satellite business ("fixed" refers to the customer, not the satellite) and will access very-small-aperture terminals (VSATs) of the type maintained by fixed satellite service purveyors like Intelsat.

FORBES: Down To Earth