公开(公告)号：US6137440A

公开(公告)日：2000-10-24

申请号：US963962

申请日：1997-11-04

Applicant: Robert S. Roeder ,  Matthew C. Smith

Inventor： Robert S. Roeder ,  Matthew C. Smith

IPC: G01R35/00 ,  G01J1/10 ,  G01J5/10 ,  G01J5/46 ,  G01K11/00 ,  G01K15/00 ,  G01R29/08 ,  H03B5/18 ,  H03B29/00 ,  G01S3/02

CPC classification number: G01K15/00 ,  G01K11/006 ,  H03B29/00 ,  H03B5/1852

Abstract: A microwave active noise source and method used for calibrating a radiometer includes a transistor configured as a noise equivalent model having a gate port, drain port and source port. During calibration of the radiometer the drain port is terminated and a bias circuit applies DC bias to the noise equivalent model. The bias circuit controls the DC bias such that a hot thermal radiation temperature and a cold thermal radiation temperature are alternately generated at the gate port of the noise equivalent model. A source inductance coupled to the source port of the noise equivalent model provides series feedback. To match the impedances in the noise source, an output matching impedance network is connected to the drain port and an input matching impedance network is connected to the gate port of the noise equivalent model. The input matching impedance network includes an input port for outputting the hot and cold thermal radiation temperatures used to calibrate the radiometer.

Abstract translation: 用于校准辐射计的微波有源噪声源和方法包括配置为噪声等效模型的晶体管，其具有栅极端口，漏极端口和源极端口。 在辐射计的校准期间，排放端口终止，偏置电路将DC偏置应用于噪声等效模型。 偏置电路控制DC偏压，使得在噪声等效模型的栅极端口交替地产生热的热辐射温度和冷的热辐射温度。 耦合到噪声等效模型的源端口的源极电感提供串联反馈。 为了匹配噪声源中的阻抗，输出匹配阻抗网络连接到漏极端口，输入匹配阻抗网络连接到噪声等效模型的门口。 输入匹配阻抗网络包括用于输出用于校准辐射计的热和冷热辐射温度的输入端口。