Tham khảo tài liệu 'microsensors, mems and smart devices - gardner varadhan and awadelkarim part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TESTING OF A MEMS-IDT ACCELEROMETER 403 of the microsensor Section . Then we will discuss the incorporation of a seismic mass to produce an inertial accelerometer Section . Measurement Setup The vector network analyser and associated calibration techniques make it possible to measure accurately the reflection and transmission parameters of devices under test3. The basic arrangement of such a measurement system is illustrated in Figure . The network analyser system consists of a synthesized sweeper 10 MHz-20 GHz the test set 40 MHz-40 GHz HP 8510B network analyzer and a display processor. The sweeper provides the stimulus and the test set provides the signal separation. The front panel of the HP 851 OB is used to define and conduct various measurements. The various other instruments are also controlled by the network analyser through the system bus. The device to be tested is connected between the test Port 1 and Port 2. The point at which Figure Basic arrangement of the measurement system for the SAW device 3 A detailed explanation of SAW parameters and their measurement is given in Chapter 11. 404 MEMS-IDT MICROSENSORS Figure Signal flow in a two-port network the device is connected to the test set is called the reference plane. All measurements are made with reference to this plane. The measurements are expressed in terms of scattering parameters referred to as s parameters. These describe the signal flow Figure within the network. parameters are defined as ratios and are represented by Sin out where the subscripts in and out represent the input and output signals respectively. Figure shows the energy flow in a two-port network. It can be shown that bl aiSu 4 22 12 and bl a I 21 4- 422 22 and therefore 11 b a S21 b Ịai when 02 0 12 b a2 S22 b2 a2 when 21 0. where 11 and 21 12 and 22 are the reflection and transmission coefficients for Port 1 2 respectively. Calibration Procedure Calibration of .
