AWR White Papers

The Importance of EM Analysis for RF/ Microwave Design

Issue link:

Contents of this Issue


Page 3 of 6

As an illustration of this process, refer back to the simple open-stub matching network shown in Figure 1. The MTRACE element at Port 1 is allowed to meander the line, and although MTRACE captures the alternating line segments and bends as MLINs and MBENDs respectively, it does not couple the parallel segments to each other, nor to the MTEE. In Figure 4, the EXTRACT block is enabled, and by using the STACKUP to define the material properties and physical dimensions of all the dielectrics and metals, the layout is automatically transferred to the EM document EM_Extract (Figure 4). It is then run/ analyzed using the AWR AXIEM analysis and the results are used in place of the elements between the two ports. This is all performed automatically, and immediately, whether the designer simulates, optimizes, tunes, or performs yield analysis. Figure 5 shows the difference for S21 for this matching network with and without the EXTRACT flow. Figure 4: A matching network schematic with the EXTRACT flow enabled showing associated elements (left), and the STACKUP element controls the mapping of the physical layers in the layout to the electrical properties for the analysis and EM document automatically created under simulation control of the schematic using EXTRACT and STACKUP blocks (right) Figure 5: Results of matching network EXTRACT flows compared to circuit models for the same element To create an EXTRACT EM document without simulating, the user simply right-clicks on either the EXTRACT block in the schematic or the schematic on the project pallet and selects Add Extraction. This makes it possible to make sure that the proper material-to-layer mappings are in the STACKUP, that the sizing of deembedding planes (if necessary) is correct, and, most importantly, that the designer has chosen a meshing grid that provides the desired simulation speed and accuracy of results metric. Note: It is also possible to include layout-only components in the EXTRACT flow, such as an element that only appears in the layout, which might occur if there are floods for power or ground, via fences for isolation, or mechanical structures that have no direct electrical representation in the schematic. To do so, select the element in the layout, right-click Shape Properties, enable the EXTRACT checkbox, and specify the name of the EXTRACT block (Figure 6). Figure 6: Arbitrary shapes in layout, not associated with an element or iNet in the schematic, can be added to EXTRACT groups, such as here, a ground fill is added to the EXTRACT flow in a 7GHz PCB power amplifier The Importance of EM Analysis for RF/Microwave Design 4

Articles in this issue

Links on this page

view archives of AWR White Papers - The Importance of EM Analysis for RF/ Microwave Design