The Loop Antennae Rules dialog is used to define which nets should be checked for loop antennae. A loop antenna is a loop formed across layers without an intervening copper plane which covers the loop area, in a high frequency track. Having this situation on a high frequency track will cause it to radiate, removing it is more ideal. Open Loops are also considered loops that are not complete but still form a loop area. This check helps identify these scenarios.
Two types of these can be checked:
- Closed Loops.
- Open Loops - These are loops that are not fully complete, but still form a loop area.
Loop Antennae are checked for using the Loop Antennae check in DRC.
The general rule matching mechanism is described here.
Shortcuts
Menu: Setup
Default Keys: T
Command: Technology
Locating this option
Available from: Setup menu > Technology option > Rules - High Speed - Loop Antennae page
Using the Loop Antennae Rules dialog
On selection, the Technology dialog opens, select Loop Antennae. The existing Loop Antennae Rules for the Technology being used will be presented.
Navigation
Press the New button to add a new entry to the list. To edit an existing entry, select it, the row will be underlined with a red line. The information can then be edited directly in the cell row or in the editing pane below it.
Remove items from the list by selecting it and pressing the Delete button.
Each line in the grid represents a separate rule, rules are used in priority from the top of the list down. Use the Up and Down buttons to re-order the rows to make them more or less significant. These rules are applied in the order defined in this list, until the first match is found. You should therefore have the more specific rules (in terms of layer, area and sub net) defined at the top of the list.
Using the Selected button will report where the selected rule is used in the Technology. Likewise, using the All button will report where all the rules in this dialog are used in the Technology.
Using the editing pane
The appropriate Loop Antennae rule is found for each net item by working down the list of rules until the first match is found. Hence, the order of the rules is important. A match is when the specified Attribute Name and Match Value match attributes of a net item. The Loop Antennae rule must have the given attribute, and its value must wildcard match the value.
Closed Loops defines whether or not to check for closed loops.
Open Loops defines whether or not to check for open loops.
Min Distance defines the distance required between a track across layers to not form an open loop. If the distance between any two segments across layers is less than this minimum distance and greater than zero, then an open loop is formed (a distance of zero would form a closed loop).
Export and Import CSV
Use the Export CSV button to export the data in your PCB design into a CSV format file. Using the Export CSV option will provide you with a formatted template ready for you to edit in your own data.
Use the Import CSV button to import data back into the PCB design using a CSV format file.
The data in the file represents a spreadsheet of dialog contents with the data headings along the top row.
Related Topics
Net Styles | Track Styles | Design Rule Check | Export CSV | Import CSV