|
|
发表于 2007-2-8 16:44:00
|
显示全部楼层
jedkey，看来Amphenol在你的心中地位挺高呢。不过我不是amphenol的。
xinshengj,关于wave port 和lumped port的区别，我在本论坛的另一个关于hfss的帖子里有说明的。你可以搜索一下我的帖子。你这2句话是看不出二者的区别的。仔细读读下面的文字，或许你就明白得多一些。
Lumped Ports
Lumped ports are similar to traditional wave ports, but can be located internally and have a complex user-defined impedance. Lumped ports compute S-parameters directly at the port. Use lumped ports for microstrip structures.
A lumped port can be defined as a rectangle from the edge of the trace to the ground or as a traditional wave port. The default boundary is perfect H on all edges that do not come in contact with the metal.
The complex impedance Zs defined for a lumped port serves as the reference impedance of the S-matrix on the lumped port. The impedance Zs has the characteristics of a wave impedance; it is used to determine the strength of a source, such as the modal voltage V and modal current I, through complex power normalization. (The magnitude of the complex power is normalized to 1.) In either case, you would get an identical S-matrix by solving a problem using a complex impedance for a lumped Zs or renormalizing an existing solution to the same complex impedance.
When the reference impedance is a complex value, the magnitude of the S-matrix is not always less than or equal to 1, even for a passive device.
Note
When a lumped port is used as an internal port, the conducting cap required for a traditional wave port must be removed to prevent short-circuiting the source。
Wave Ports
By default, the interface between all 3D objects and the background is a perfect E boundary through which no energy may enter or exit. Wave ports are typically placed on this interface to provide a window that couples the model device to the external world.
HFSS assumes that each wave port you define is connected to a semi-infinitely long waveguide that has the same cross-section and material properties as the port. When solving for the S-parameters, HFSS assumes that the structure is excited by the natural field patterns (modes) associated with these cross-sections. The 2D field solutions generated for each wave port serve as boundary conditions at those ports for the 3D problem. The final field solution computed must match the 2D field pattern at each port.
HFSS generates a solution by exciting each wave port individually. Each mode incident on a port contains one watt of time-averaged power. Port 1 is excited by a signal of one watt, and the other ports are set to zero watts. After a solution is generated, port 2 is set to one watt, and the other ports to zero watts and so forth.
Within the 3D model, an internal port can be represented by a lumped port. Lumped ports compute S-parameters directly at the port. The S-parameters can be renormalized and the Y-matrix and Z-matrix can be computed. Lumped ports have a user-defined characteristic impedance. |
|
IP卡
狗仔卡
显身卡