Development of MM-Wave Transistor Amplifiers for Focal Plane Arrays

这些资金支持了一项为期三年的努力，以开发低噪音 毫米波用低温晶体管放大器 射电天文学 晶体管放大器提供了许多 射电天文学系统的重大优势，包括 极低（Tn 65 K SSB）噪声，大（10 - 20 GHz）瞬时 带宽，单边带系统操作，无需输入滤波器， 稳定性好。 特别是有额外的优点， 焦平面阵列系统的重要性。 这种系统 在操作温度和其他方面相对不重要 条件和他们很好地适应繁殖在 阵列所需的数量。 没有机械调整， 以获得最佳性能。 执行情况预测 的HEMT放大器在3毫米波段是接收机噪声温度 低于65 K（单边带），应产生大气- 在大多数频率下性能有限。 大带宽将 便于在大范围内搜索多条谱线 频率范围以及来自具有 未知速度。 目前可用的设备提供了非常 40 - 50 GHz范围内的低噪声性能， 将指导初步努力。 两年内， 在3 mm波长范围内的性能相当， 可获得的。

These funds support a three year effort to develop low-noise cryogenic transistor amplifiers for use in millimeter wavelength radio astronomy. Transistor amplifiers offer a number of significant advantages for radio astronomical systems, including very low (Tn 65 K SSB) noise, large (10 - 20 GHz) instantaneous bandwidth, single sideband system operation without input filters, and good stability. There are additional virtues of particular importance for focal plane array systems. Such systems are relatively non-critical in terms of operating temperature and other conditions and they are well-adapted to reproduction in the quantities required for arrays. No mechanical adjustments are required for optimum performance. Projections for the performance of HEMT amplifiers in the 3 mm band are receiver noise temperatures below 65 K (single sideband), which should yield atmospheric- limited performance at most frequencies. The large bandwidth will facilitate searches for multiple spectral lines over a large frequency range as well as for emission from galaxies having unknown velocities. Presently available devices offer extremely low noise performance in the 40 - 50 GHz range, which is where initial efforts will be directed. Within two years, devices with comparable performance in the 3 mm wavelength range should be obtainable.