Microwave Office Training

Transcription

1 Microwave Office Training Schematic Layout Schematic Layout Schematic View Circuit We are Here! Schematic Layout View External World Need Export Mapping Two views of the same circuit! - including connectivity (ratslines) Need Cell Faces or Cell Pins External World GDSII DXF Artwork Cells 2 Schematic Layout 1

2 Summary - Schematic and Layout The Circuit has two different views Schematic View: The traditional Schematic Layout View: The traditional Layout The two views are related Connectivity of Elements Physical Parameters of PCells - length, width,... PCells have two properties menus Element Properties control the parameters, symbol,... Shape Properties control what layers, how snaps together... Connectivity Schematic View: Nodes connected by wires Layout View: Elements connected at faces 3 Schematic Layout Schematic and Layout Views Schematic View Schematic Layout View Electrical Model of Element Note: Not all elements have layout Layout and Connectivity Parameterized Cells (PCells) Can also draw shapes - ground fills, etc. Remember - These are Drawing Layers! 4 Schematic Layout 2

3 Example Board Stackup This is configured as a Library: AWR_4Layer_PCB FR4 - Er = 3.38, tand 1 GHz Conductors - Copper, Thickness = 1.4 mil Dielectric Layers - 25 mil thick Via Layers Dielectric Layers Microstrip Metal Layers AWR_Top_Copper AWR_Via12 AWR_PCB1 Ground and Coplanar Lines Stripline Ground AWR_Via23 AWR_Via34 AWR_PCB2 AWR_PCB3 AWR_Mid_Ground AWR_Mid_Copper AWR_Bottom_Ground Tip: Use easy to identify names! (These all have AWR_ in front of them.) Helps when layers are added. 5 Schematic Layout Simple Layout- Schematic Manipulations Step 1: Open a New Project - File > New With Library > AWR_4Layer_PCB. - You need to browse to the 4layerPCB.ini, the first time you use the library. Step 2: Make New Schematic - My Tee. Note - This is an icell - ($ in name). It knows how big to make itself. My Tee 6 Schematic Layout 3

4 PCells - Simple Manipulation Schematic View Layout View Selection/ Highlight Move Tip: Schematic and Layout know about connectivity - but only Layout knows about position Resize Can Grab Handles to change size 7 Schematic Layout PCells - Shape and Element Properties Schematic Schematic Layout Can only get to Element Properties Can get to Shape or Element Properties Either double click element - or RC > Properties. Element Properties Must RC element. Shape Properties Substrate Used Physical Parameters Symbol Layout Model Options (Extract, Spice Model...) 8 Schematic Layout LINETYPE Selection Model Layer Mapping Freezing, Anchoring, etc. Face Settings (How connects) 4

5 PCells - Connectivity Model Elements have nodes Wires connect the nodes Connectivity shown by ratslines Connected at faces Can draw a shape (example - ground flood) - but doesn t have any notion of connectivity What if we want to create or import shapes with connectivity? Create them as an artwork cell with cell ports and/or area pins. We then can use them in Schematic Layout. 9 Schematic Layout Snapping Together the Layout Autosnap Unsnapped Snapped Schematic Layout Toolbar Snapping makes connecting together the elements easier Has many options and settings Grid Options Autosnap versus manual snapping Anchoring elements, etc. 10 Schematic Layout 5

6 Simple Layout- Schematic Manipulations - 2 Step 3: Go into Schematic Layout and Move Objects to about Right Shape. Beginning Get Them Reasonably Close Select all and AutoSnap 11 Schematic Layout The Grid Layout works on a Grid - Important for two reasons - Easy movement and placement -Can Align objects more Easily Note: The grid and database are set in Layout Options. Grid Spacing - Size of the Grid Database Unit Size - Smallest Size in the Database (Set to about ½ the tolerance of the process) Rotation Snap Angle - Allowed angles of rotation Step 4: Change the Grid Settings to 10X in the example and move around the cells. Step 5: Make the multiplier small (.1X) and try lining up objects. 12 Schematic Layout Options > Layout Options Schematic Layout Toolbar Grid Multiplier 6

7 Faces and Snapping Elements Connect at Faces When Snapping two elements together Select first element - which will stay fixed and second element - which will snap to it Step 6: Pull the Tee pieces apart - and put them back together one piece at a time going from left to right. In a few slides - we ll cover options for Faces 13 Schematic Layout Options for Controlling Snapping Options > Layout Options Snap Together Options -Auto snap on parameter changes - Manual snap for all objects - Manual snap for selected objects only Rotation Allowed during Snapping? Default connection to closest face. Controls how and when Auto Snapping Occurs Tip: For normal usage the following options are useful - Manual snap for selected objects only. Don t rotate. Default to closest face. 14 Schematic Layout 7

8 Snapping More Control 1. Manual Snap for selected objects only - Won t do anything unless you select objects (Ctrl - A for select all.) 2. Manual Snap for all objects. - All objects snap together when touch button. 3. Auto Snap on parameter changes - Anything that affects layout will cause autosnap. More Automatic 15 Schematic Layout Autosnap Options Select Two items in the Tee and try Autosnap with: Manual Snap for Selected Objects Manual Snap for All Objects Step 7: Change a Parameter with Autosnap on Parameter Changes Set. 16 Schematic Layout 8

9 Faces Connection Options Step 8: Right click on Layout object > Properties > Faces. Can Force Selection of what it snaps to Each Face has a Number The face will highlight Face 1 - Center Justification 17 Schematic Layout Faces Connection Options - 2 Step 9: Bring in a Transistor Package Artwork Cell Import GDS Library - transistor.gds This is an Artwork Cell (GDSII). Tip: The cell ports are hard to see. Change them to black, solid, lines. Step 10: Determine what drawing layers are being used. What layers are the cell ports using? Note - There are 4 cell ports - with two labeled port 3: 3a and 3b. 18 Schematic Layout 9

10 Faces Connection Options - 3 Step 11: Associate the Artwork cell layout with a schematic element - a FET. - Create a schematic - Transistor. Properties > Layout Any FET will do - we are looking at layout here. (This one is Linear Devices > FET) 19 Schematic Layout Pick four_tab Note: All 3 port devices are shown as choices Faces Connection Options - 4 Step 12: Add MLINs to the transistor - two of them to the source. Lines Misconnected at Source 20 Schematic Layout 10

11 Faces Connection Options - 5 Want second source line on other package tab - port 3 Step 13a: Select the right face - 3b. Step 13b: Make it connect to the right line 21 Schematic Layout Faces Connection Options - 6 Flip or Rotate 180 degrees to get oriented correctly Note: If we set snapping to Default to closest face... this would automatically work. 22 Schematic Layout 11

12 Faces Connection Options - 7 Variable - Connection Point Slides along the Face Step 14: Change the Face Justification and See the Effect on snap Together Offset - Controls Position of Connection dx - along face dy - perpendicular to face angle - line snaps to an angle 23 Schematic Layout More Snapping Options Connection to Closest Face - Try the line on the source both ways Auto Face Inset - Solves the problem of angled lines not touching when snapped to grid Tip: In normal layout operation, this is a good option. Fixed Origin Options - By default, any sub-circuit keeps port 1 immobile. 24 Schematic Layout 12

13 Anchor, Freeze, and Stretch to Fit Anchor - Cell Can t move during snapping Freeze - Cell Can t move for anything Step 15: Add another MLIN to My Tee 25 Schematic Layout Leave a gap in the layout Anchor, Freeze, and Stretch to Fit - 2 Anchor the lower MLIN: Properties > Anchor Case 1: Snapping top MLIN To bottom moves top MLIN... - even if you select top MLIN first. Note the red cross to show it s anchored Case 1 Case 2: Let MLIN stretch to fit Properties > Stretch to Fit and snap the two elements Schematic Edit Toolbar Case 2 Or you can use Stretch to Fit 26 Schematic Layout 13

14 Layout and Subcircuits Subcircuits will have their layout appear in the upper layout Can descend into the subcircuit s layout and edit it All Instances will change when you do this Step 16: Add ports to the schematic My Tee in preparation of making this a subcircuit Note: If you don t have ports - there is no way to know where the connections should be. 27 Schematic Layout Layout and Subcircuits - 2 Top Level. Step 17: Create a schematic - Top Level - and connect two sub-circuits of My Tee together with an MLIN. Note: Subcircuits can be added by: Ctrl - K, or Draw > Subcircuit. 28 Schematic Layout 14

15 Layout and Subcircuits - 3 Step 18: Descend into the left subcircuit -select and edit in place with: -or double click and edit the instance Cell Edit Toolbar Change the layout of one of the subcircuits - Notice that both layouts change. Note: You will have to click F5 - before all instances update. Tip: Subcircuits might move around on you if you are changing them - if so, try Options > Layout > Fixed Origin for Subcircuits. 29 Schematic Layout 3D View Area Can select an area of layout to view in 3D Step 20: Select - Draw > 3D Clip Area. 3D View Can resize and move this area like any shape Cell Edit Toolbar 30 Schematic Layout 15