Tài liệu RF và mạch lạc lò vi sóng P5 pptx

... at RF and microwave frequencies. As shown in Figure 5.1, impedance matching networks are employed at the input and the output of an ampli®er circuit. These networks may also be needed to perform some ... on the upper scale of the Smith chart. Moving from this point toward the load (that is counterclockwise), open-circuit admittance (zero) is found ®rst. Moving further in the same direction,...

Ngày tải lên: 15/12/2013, 11:15

... comprising resistors, inductors, capacitors, and dependent sources. Thus, it may include electronic devices but not the independent sources. Further, it has four terminals, two for input and the other ... output of the signal. There may be a few more terminals to supply the bias voltage for electronic devices. However, these bias conditions are embedded in equivalent dependent sources. Hence,...

Ngày tải lên: 24/12/2013, 17:15

... areas where RF technology is being applied. While some of these applications have traditionally used infrared (IR) technology, current trends are moving toward RF. The fact is that RF is superior ... system. Figures 1.3 and 1.4 list selected devices used at RF and microwave frequencies. Solid-state devices as well as vacuum tubes are used as active elements in RF and microwave circui...

Ngày tải lên: 15/12/2013, 11:15

... This chapter begins with an overview of microwave communication systems and the radio frequency wireless services to illustrate the applications of circuits and devices that are described in the ... D t is the directivity of transmitting antenna. Power collected by the receiving antenna is P r  A er w t 2:4:19 From (2.4.6), A er  l 2 4p G r 2:4:20 where the receiving antenna gain is ......

Ngày tải lên: 15/12/2013, 11:15

... converted to corresponding impedance by moving to a point on the diametrically opposite side of the VSWR circle. It shows a normalized load impedance as 2  j2. Moving from this point by 3.15 l toward ... impedance Z L to a 70 TRANSMISSION LINES Measurementof Impedance Impedance of a one-port microwave device can be determined from measurement on the standing wave at its input. Those required...

Ngày tải lên: 15/12/2013, 11:15

... air-®lled circular cylindrical cavity that resonates at 9 GHz in TE 011 mode. It should be made of copper and its height should be equal to its diameter. Find Q of this cavity. 22. Design a TE 01d mode ... frequencies from a wide signal spectrum. Resonant circuits provide such ®ltering. There are well-developed,sophisticated methodologies to meet virtually any speci®cation. However,a simple c...

Ngày tải lên: 15/12/2013, 11:15

... k 2 r  0:0247 which is approximately one-fourth of the previous (two-section transformer) case. 218 IMPEDANCE TRANSFORMERS Z 1 is obtained by solving the equation (6.6.18) as follows, Z L À Z o tan 2 y z  Z 2 1 Z o  ... as well. Exact formulation of the multisection impedance transformer is conveniently developed via the power loss ratio, P LR , de®ned as follows: P LR  Power loss ratio ...

Ngày tải lên: 15/12/2013, 11:15

... method is more powerful in the sense that it provides a speci®ed response of the ®lter. Both of these techniques are included in this chapter. It concludes with a design overview of microwave ... preceding section provides a simple design procedure. However, transfer characteristics of this circuit cannot be shaped as desired. On the other hand, the insertion loss method provides ways to shap...

Ngày tải lên: 24/12/2013, 17:15

... SIGNAL-FLOW GRAPH REPRESENTATION OF A PASSIVE SINGLE-PORT DEVICE Consider load impedance Z L as shown in Figure 9.18. It is a single-port device with port voltage and current V L and I L ,respectively. ...  Z S Z o  V ref S  E S À 1À Z S Z o  V in S or, V ref S  Z o Z o  Z S E S À Z o À Z S Z o  Z S V in S Dividing it by  2Z o p ,we ®nd that V ref S  2Z o p  Z o Z o ...

Ngày tải lên: 24/12/2013, 17:15

... source terminal of the MESFET via inductor L S . Capacitor C S grounds the source at RF while L S blocks it from the dc supply. Inductor L G grounds the gate for dc while stopping the RF. Similarly, bias ... S 21  6 180  Determine the maximum gain possible with this transistor and design an RF circuit that can provide this gain. (i) Stability check: k  1 ÀjS 11 j 2 ÀjS 22 j 2 jDj 2...

Ngày tải lên: 24/12/2013, 17:15