Tài liệu RF và mạch lạc lò vi sóng P8 ppt

... devise some way to control its attenuation around the cutoff. Expression for the propagation constant of a T-section is listed in Table 8.1. In order to ®nd g of this T-section, we ®rst divide ... two-port network. Filters have been designed using active devices such as transistors and operational ampli®ers, as well as with only passive devices (inductors and capacitors only). Therefore, thes...

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

... re¯ection coef®cient of 0.2 is acceptable, circuits (iii) and (iv) can provide much wider bandwidth in comparison with those of the previous example. This concept can be used to shape the re¯ection coef®cient ... signal generator. It is to be matched with a 100-O load. Design a matching circuit that provides perfect matching over the frequency band of 1 kHz to 1 GHz. Determine power delivered...

Ngày tải lên: 15/12/2013, 11:15

... such requirements. The chapter begins with the single-section impedance transformer that provides perfect matching at a single frequency. Matching bandwidth can be increased at the cost of a higher ... Hence, G in   L 0 dG in  1 2  L 0 e Àj2bz d dz ln  Zdz 6:7:3 Therefore, G in can be determined from (6.7.3) provided that  Zz is given. However, the synthesis problem is a bit compl...

Ngày tải lên: 15/12/2013, 11:15

... Z o2 Z 2  Z o2  b 2 a 2 7:6:22 Dividing (7.6.17) by a 1 and then using (7.6.21), we ®nd b 1 a 1  G 1  Z 1 À Z o1 Z 1  Z o1  S 11  S 12 a 2 a 1  7:6:23 Now, dividing (7.6.18) by a 2 and then ... jb, the network becomes lossless. In that case, S 11 S 12 S 21 S 22 !  0 e Àjb` e Àjb` 0 ! Obviously, it is a unitary matrix now. Example 7.19: Find scattering parameters of the two-por...

Ngày tải lên: 24/12/2013, 17:15

... nonlinear active device. In addition, since the device is producing RF power, it must have a negative resistance. The basic principle of an oscillator circuit can be explained via a linear feedback system ... Abrupt junction diodes provide very high Q and also operate over a very wide tuning voltage range (typically, 0 to 60 V). These diodes provide an excellent phase noise performance beca...

Ngày tải lên: 24/12/2013, 17:15

... applications and circuit design. In RF and Microwave Circuit Design for Wireless Communications, L. E. Larsen (ed). Boston: Artech House, 1996. B. Razavi, RF Microelectronics. Englewood Cliffs, ... bandwidth of an antenna is de®ned as the frequency band over which its performance with respect to some characteristic (HPBW, directivity, etc.) conforms to a speci®ed standard. Polarization Po...

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 ... transformer is also presented along with a few examples to match resistive loads. Impedance measurement via the voltage standing wave ratio is then discussed. Finally, the Smith chart is int...

Ngày tải lên: 15/12/2013, 11:15

... CIRCUITS If the cavity is made of a perfect conductor and ®lled with a perfect dielectric then it will have in®nite Q. However,it is not possible in practice. In the case of cavity walls having a ®nite ... 3417,respectively. Substituting these into (4.5.5), Q of this cavity is found to be 2106. Circular Cylindrical Cavities Figure 4.20 shows the geometry of a circular cylindrical cavity of ra...

Ngày tải lên: 15/12/2013, 11:15

... 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