Abstract:
Apparatus for providing a controllable impedance at a reference plane in a circuit comprises a unidirectional transmission line loop having first and second input/output terminals. The first input/output terminal is connected to the reference plane and an amplifier is located in the transmission line loop to amplify signals passing in a direction from the second input/output terminal to the first input/output terminal. A variable tuned circuit couples the second input/output terminal to a terminating device.
Abstract:
A novel method is described that enables the measurement of the phase of the spectral components generated by an harmonic phase reference generator without using a calibrated sampling oscilloscope. First one uses a vector network analyzer to measure the output reflection coefficient of an harmonic phase transfer standard and of the harmonic phase reference generator that needs to be characterized. Next one connects the transfer standard to a microwave receiver and one measures the spectral components that are generated by the transfer standard. One then connects the harmonic phase reference generator to be characterized to the microwave receiver. The spectral components of the harmonic phase reference generator to be characterized are calculated by using the spectrum of the transfer standard as measured by the receiver. The spectrum of the harmonic phase reference generator to be characterized as measured by the receiver and the known spectrum of the transfer standard.
Abstract:
Radio Frequency (RF) signal network measurement data of a device under test are acquired by exciting the device using a modulated RF excitation signal, while measuring RF signal data at the signal ports of the device, measuring bias signal data, and processing the RF signal data and the bias signal data, providing the RF signal network measurement data of the device. By acquiring bias signal data, in particular by measuring variations in the bias signals, a more accurate and reliable characterization of the non-linear behavior of the device under test can be provided. A Non-linear Network Measurement System (NNMS) is arranged for acquiring the RF and biasing signal data and characterizing the non-linear signal behavior of a device under test.
Abstract:
An apparatus for collecting RF signal measurement data at signal ports of an RF and microwave device-under-test (DUT). The apparatus comprises means for measuring incident and reflected RF signals at the signal ports of the DUT. Synthesizer means for generating RF signals at a fundamental frequency and higher harmonics. Tuner means arranged for loading the DUT under different impedance conditions for the fundamental frequency and higher harmonics, and means for feeding the RF signals of the synthesizer means to the signal ports of the DUT. The apparatus may form part of a Non-linear Network Measurement System (NNMS).
Abstract:
A calibration procedure for a real-time load-pull system whereby the signal passes through at least one of the tuners of said real-time load-pull system. A calibration standard is connected to the test ports and an electromagnetic wave signal passes through one of the tuners before passing through the wave sensing structure. After having passed the wave sensing structure the electromagnetic wave signal interacts with the calibration element. This results in a reflected and eventually a transmitted electromagnetic wave signal that pass through the wave sensing structures of the system. The sensed electromagnetic wave signals are measured by means of a receiver. The procedure is repeated with different calibration standards. Then a line element is connected to the test ports and, one after the other, a set of calibration standards, a power meter and a harmonic phase reference generator are connected to the output tuner, each time sending a signal and measuring the wave signals. The measured data is used to calculate the error coefficients of the real-time load-pull system.
Abstract:
An impedance tuning measurement setup and method for characterizing high frequency devices-under-test whereby one inserts an extremely low loss directive coupling structure between the terminal of the device-under-test and that part of the impedance tuner that generates the variable impedance. One or both coupled arm outputs of the directive coupling structure are connected to the inputs of a broadband RF receiver. By using the extremely low loss directive coupling structure one avoids the loss of energy caused by the distributed directional couplers or the resistive bridges used in prior art. The low loss directive coupling structure is formed by a small piece of conductive wire, which is inserted into the electro-magnetic waveguiding structure that guides the RF signals towards and from the DUT terminals. The ends of the small piece of conductive wire are connected to the center conductors of two electromagnetic waveguiding structures, which act as the coupling arms.
Abstract:
The values of the 6 complex parameters of a large-signal S-parameter model of a high frequency device-under-test are determined by using a frequency-offset probe-tone method. A relatively large one tone signal is applied to the input port of the device and a relatively small one tone signal having a frequency offset relative to the frequency of this large one tone signal is applied to the output port of the device. The 6 large-signal S-parameters are found by measuring and processing the spectral components of the incident and the scattered voltage waves at the device signal ports. These spectral components appear at 3 frequencies: at the frequency of the large one tone signal, at the frequency of the small one tone signal and at the frequency of the large one tone signal minus the frequency offset of the small one tone signal.
Abstract:
A method of and an arrangement for characterizing non-linear behavior of RF and microwave devices under test in a near matched environment. The method comprises the steps of exciting the device by an RF signal under different load conditions, measuring signal data at input and output ports of the device, verifying whether the measurement data meet predetermined quality criteria; calculating, from the measurement data, model parameters of a predetermined model for characterizing the non-linear behavior of the device, and verifying assumptions made in the characterization model by collecting additional measurement data and comparing same with data calculated from the model using the model parameters calculated. The load conditions are obtained by connecting to the output port of the device a matched load, an open, a short and a plurality of attenuators and delays.
Abstract:
An envelope behavioral model is developed and used in a system and method that simulates and predicts outputs of a non-linear component. An analyzer generates a test signal which is provided as input to the non-linear component. Model kernels representative of static and dynamic parts of the model are extracted from an output of the non-linear component responsive to the test signal. The dynamic part represents memory effects of the non-linear component. The model kernels are then used by a simulator to predict the output of the non-linear component responsive to signals of a modulation type.
Abstract:
A method and system for predistorting signals provides a test signal to model a non-linear component. Model kernels representative of static and dynamic parts of the model are extracted from an output of the non-linear component responsive to the test signal. The dynamic part represents memory effects of the non-linear component. The model kernels are then used to calculate an inverse memory model component model. An input signal is predistorted using the inverse memory model.