17.2 Impedance Calculation
High Frequencies. Reliable Fault-Free Operation.
Higher transmission frequencies, shorter pulse rise times, and quicker communication between components. And right at the center – the PCB with its conductors acting as an important transmission line. High-frequency applications place increasingly high demands on the assembly, and require powerful and fault-free impedance behavior. For the PCB specifically, if transmission errors are to be avoided, a number of influencing factors need to be taken into account across all stages of PCB development – from layer stackup and the layout right through to production.
Thanks to our long-standing experience with high-frequency PCBs, we understand just how complex and sensitive impedance values can be, and we provide tailored support with both theoretical calculations and practical optimizations. With our state-of-the-art software, you can model your PCB stackup and accurately simulate any changes to the conductor parameters. We use real process experience and production tolerances to predict the exact impedance characteristics of your PCB, and we work with you to optimize these characteristics if necessary.
Thanks to our long-standing experience with high-frequency PCBs, we understand just how complex and sensitive impedance values can be, and we provide tailored support with both theoretical calculations and practical optimizations. With our state-of-the-art software, you can model your PCB stackup and accurately simulate any changes to the conductor parameters. We use real process experience and production tolerances to predict the exact impedance characteristics of your PCB, and we work with you to optimize these characteristics if necessary.
KSG Impedance Calculation Services + Advantages
- Review and optimization of impedances and layer stackups during your CAD conception and design phase
- Creation of a layer stackup with calculation of the impedance structures – also in conjunction with complex rewiring strategies
- Calculation and optimization of the layer stackup and the conductors affected by impedance based on real conductor geometries as well as material- and process-related tolerances
- Impedance measurement and logging on separate impedance measurement lines
- Advice on the cost-effective creation of the impedance measurement coupon to be included on your sub-panel
Software Tools and Measuring Technology
The following software tools and measuring technologies are used at KSG:
- Polar SI8000 impedance calculation software
- Polar CouponGenerator for generating a separate impedance measurement coupon
- CITS 880s 4-channel impedance meter from Polar Instruments for measuring single-ended and differential impedance values
- Datalog Report Generator for statistical analysis and logging of measured values
Forms of Impedance Calculation and Control
| KSG test/recording concept | >>Practical<< impedance control (with measurement) | >>Theoretical<< impedance control (without measurement) | Production without impedance control |
|---|---|---|---|
| Stackup planning and impedance calculation | ✓ | ✓ | - |
| Adjustment of impedance conductor widths | ✓ | ✓ | - |
| Design an mounting of coupons | ✓ | - | - |
|
Loss of net space due to test coupons | ✓ | - | - |
|
Measurement/recording of impedance values | ✓ (Log, test coupon can be supplied on request) | - | - |
| Additional time and costs | Calculation, adjustment, coupon creation, measurement | Calculation only, adjustment (time) | - |
| Application | Recommended for critical circuits (= standard) | Cost-effective alternative for designs that are fairly “insensitive” or have already been confirmed | Implementation of specified data, dimensioning of impedance conductors is the responsibility of the customer |
Keywords
- Impedance calculation
- High frequency
- Controlled impedance
- Calculations and simulations