How to accurately measure the line loss of RF line? This is a question many people want to ask. For laymen, this question is very difficult! Today, the editor will introduce this issue to you, hoping to help you.
RF circuit layout to reduce parasitic signals, RF engineers need to play a creative role. Keeping these eight rules in mind can not only accelerate the product launch process, but also improve the predictability of the work schedule.
All the current flowing through the distributed line has equal backflow. Although there are many coupling strategies, backflow usually flows through adjacent grounding layers or grounding arranged in parallel with signal lines. When the reference layer continues, all coupling is limited to the transmission line and everything is normal. However, if the signal line is switched from the top layer to the inside or the bottom layer, the backflow must also obtain the path.
1. Test with TDR method, namely time domain reflection.
2. Time Domain reflectometer TDR(Time-Domain Reflectometry) technology. This technique involves generating a time step voltage that propagates along the transmission line. Use oscilloscope to detect the reflection from impedance, measure the ratio of input voltage to reflected voltage, and then calculate discontinuous impedance.
3. Calculate and display the network step and impulse response of the network as a function of time by using the data measured by network analyzer in frequency domain. The traditional TDR capability in reflection and transmission increases the potential of measurement in band-limited networks.
In the reflection mode, network analyzer measure the reflection coefficient as a function of frequency. The reflection coefficient can be regarded as the transfer function of incident voltage and reflected voltage. Inverse transformation converts the reflection coefficient into a time function (impulse response). You can use the convolution of the reflection coefficient and the input step or pulse to calculate the step and impulse response. In transmission mode. Network Analyzer measure the transfer function of the two-port device as a frequency function. Inverse transformation converts the transfer function into the impulse response of the two-port device. Calculate the step and impulse response by convolution of the impulse response and the input step or pulse.
Now do you know how to accurately measure the line loss of RF line? I hope today's article can help you solve your doubts.
