Abstract: A PIM measurement circuit enables making forward and reverse PIM measurements on any 1 port (reflection) or 2 port (transmission) device with the ability to determine in distance where individual PIM impairments are located as well as their magnitude. The PIM measurement circuit includes two frequency sources that are provided through a combiner for a CW characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a saw tooth offset sweep generator attached to one of the two frequency sources. With downconversion and processing of signals from the PIM impairments, the FM signal provides a frequency variation that is converted using a Fourier transform or spectrum analysis for separation of frequencies, enabling determination of the distance of the PIM sources as well as their magnitudes.

Abstract: A small light-weight battery operated calibrator device provides a precise sine wave output for use in calibration of test equipment, such as a RF Power Meter or a Spectrum Analyzer. The calibration device includes two power levels, one ?40 dBm and one 0 dBm. The purpose of the two power levels is to obtain a slope and offset for correction of the RF power measuring device being calibrated. Operation indication LED lights are provided to indicate which of the two powers are in use, and if battery power is below acceptable levels. Miniature low power components including a crystal oscillator and a divide by 2 integrated circuit that generates a precise square wave and a low pass filter for converting the square wave into a precise sine wave allows the calibrator to be battery operated and stored as a calibration component.

Abstract: A distance to PIM measurement circuit is made using a device such as an AWS transceiver that has separate transmit and receive bands. With a typical AWS transceiver placed in close proximity to a PCS transceiver, the AWS device will include a band reject filter to eliminate interference from the PCS signals. The PIM measurement circuit includes two frequency sources F1 and F2 that are provided through a combiner for characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a offset sweep generator attached to one of the two frequency sources. To avoid frequencies blocked by the band reject filter, a desired harmonic of a test PIM harmonic signal is selected outside the band of the band reject filter.

Abstract: A small light-weight battery operated calibrator device provides a precise sine wave output for use in calibration of test equipment, such as a RF Power Meter or a Spectrum Analyzer. The calibration device includes two power levels, one ?40 dBm and one 0 dBm. The purpose of the two power levels is to obtain a slope and offset for correction of the RF power measuring device being calibrated. Operation indication LED lights are provided to indicate which of the two powers are in use, and if battery power is below acceptable levels. Miniature low power components including a crystal oscillator and a divide by 2 integrated circuit that generates a precise square wave and a low pass filter for converting the square wave into a precise sine wave allows the calibrator to be battery operated and stored as a calibration component.

Abstract: A PIM measurement circuit enables making forward and reverse PIM measurements on any 1 port (reflection) or 2 port (transmission) device with the ability to determine in distance where individual PIM impairments are located as well as their magnitude. The PIM measurement circuit includes two frequency sources that are provided through a combiner for a CW characterization of the PIM circuit. To enable distance determination, an FM measurement is created by using a saw tooth offset sweep generator attached to one of the two frequency sources. With downconversion and processing of signals from the PIM impairments, the FM signal provides a frequency variation that is converted using a Fourier transform or spectrum analysis for separation of frequencies, enabling determination of the distance of the PIM sources as well as their magnitudes.

Abstract: A small light-weight battery operated calibrator device provides a precise sine wave output for use in calibration of test equipment, such as a RF Power Meter or a Spectrum Analyzer. The calibration device includes two power levels, one ?40 dBm and one 0 dBm. The purpose of the two power levels is to obtain a slope and offset for correction of the RF power measuring device being calibrated. Operation indication LED lights are provided to indicate which of the two powers are in use, and if battery power is below acceptable levels. Miniature low power components including a crystal oscillator and a divide by 2 integrated circuit that generates a precise square wave and a low pass filter for converting the square wave into a precise sine wave allows the calibrator to be battery operated and stored as a calibration component.

Abstract: An output amplifier stage covers a flat frequency range of DC to microwave frequencies with provisions for independent control of input and output DC offset. The output amplifier stage includes a standard AC coupled microwave amplifier for high frequency performance. The AC coupled amplifier is intended for use as an output stage in a pulse pattern generator, although it can be used in any application where broadband frequency operation is needed with control of DC at its input and output. The DC control is provided using circuitry providing a DC bypass path around an AC coupled amplifier. The bypass path is provided between two Bias T circuits, one Bias T before and one Bias T after the AC coupled amplifier. An adjustable DC bias offset is further provided to the AC amplifier input. A feed forward signal is further provided from the input to the output of the AC coupled amplifier to supply a missing DC and low frequency component to the AC coupling of the high frequency amplifier stage.

Abstract: Circuitry is provided to drive a step recovery diode (SRD) (8) in a sampler based vector network analyzer (VNA) that allows harmonic samplers (10, 11) to operate over many octaves. The circuit includes a digital pulse generator (FIG. 5) for providing a LO signal. The LO signal is provided over an octave frequency range as in previous SRD driver circuits, but pulse forming circuitry is provided to decrease the pulse rate to a sub multiple of the LO generating oscillator signal. The pulse forming circuitry includes a programmable frequency divider (50) to vary the pulse rate. The pulse forming network further includes registers (50, 52) connected to the programmable frequency divider (50) to limit the pulse width resulting in reduced heating of the SRDs. With an effectively wider frequency operation range using the SRD (8), only one downconversion is required in the VNA, eliminating the need for additional mixers (30, 31) and a second LO signal generator (24) to provide a second downconversion.

Abstract: A small light-weight battery operated calibrator device provides a precise sine wave output for use in calibration of test equipment, such as a RF Power Meter or a Spectrum Analyzer. The calibration device includes two power levels, one ?40 dBm and one 0 dBm. The purpose of the two power levels is to obtain a slope and offset for correction of the RF power measuring device being calibrated. Operation indication LED lights are provided to indicate which of the two powers are in use, and if battery power is below acceptable levels. Miniature low power components including a crystal oscillator and a divide by 2 integrated circuit that generates a precise square wave and a low pass filter for converting the square wave into a precise sine wave allows the calibrator to be battery operated and stored as a calibration component.

Abstract: A Pseudo Random Bit Sequence (PRBS) generator is provided with components to enable operation at very high microwave frequencies with inexpensive components. The PRBS generator initially replaces the D flip-flops of a conventional PRBS generator with delay lines connected in a similar manner. Further, an exclusive OR (EXOR) gate used in a conventional device is replaced in one embodiment by a mixer and amplifier. In another embodiment, the EXOR gate is replaced by a Gilbert Cell. In some embodiments, complementary outputs of an EXOR gate are connected to separate delay lines to reduce components needed for the PRBS generator.

Abstract: An output amplifier stage covers a flat frequency range of DC to microwave frequencies with provisions for independent control of input and output DC offset. The output amplifier stage includes a standard AC coupled microwave amplifier for high frequency performance. The AC coupled amplifier is intended for use as an output stage in a pulse pattern generator, although it can be used in any application where broadband frequency operation is needed with control of DC at its input and output. The DC control is provided using circuitry providing a DC bypass path around an AC coupled amplifier. The bypass path is provided between two Bias T circuits, one Bias T before and one Bias T after the AC coupled amplifier. An adjustable DC bias offset is further provided to the AC amplifier input. A feed forward signal is further provided from the input to the output of the AC coupled amplifier to supply a missing DC and low frequency component to the AC coupling of the high frequency amplifier stage.

Abstract: Selectable attenuators are used in the reference and test paths of a VNA, with attenuation automatically inserted or deleted when the Device Under Test (DUT) attenuation reaches predetermined thresholds. Attenuation in the reference channel is removed when the signal in the test channel is sufficient to overcome the leakage of the reference channel. Additionally, attenuation is removed from the test channel when the reference channel has a high attenuation inserted to further increase the difference between the leakage reference signal and the reduced test channel signal thus allowing lower isolation requirements on the two (or more) receiving channels.

Abstract: A differential reflection bridge is provided for a 100 Ohm load, the bridge not being compromised by a translation to a 50 Ohm system. The reflection bridge uses two transmission line baluns. The first traditional balun T1 connects the input signal source to a resistor bridge. The second balun T2 connects between a central node of the resistor bridge and an output OUT as well as a second test port that eliminates a path to ground. With no ground path the bridge is immune to common mode impedance disturbances.

Abstract: A method and apparatus are used to calibration a Vector Network Analyzer (VNA). The method includes providing a calibration module with a single port, providing within the calibration module a set of reflecting components with known scattering parameters, providing control signals to the calibration module through the single port, providing the known scattering parameters to the VNA through the single port, coupling one of reflecting components to the VNA, measuring scattering parameters, and comparing the measured scattering parameters with the known scattering parameters. The apparatus includes a calibration module and a controller module. In one embodiment, the calibration module includes a set of reflecting components, a memory that stores the characterization data, and a current source which sends characterization data in the form of current pulses to the controller module. The controller module includes a voltage source that generates the control signals used by the calibration module.

Abstract: A handheld Vector Network Analyzer (VNA) is provided with circuitry capable of providing operation over a very wide bandwidth. The VNA includes two reflectometers, a first high frequency reflectometer (150) such as the model S331 Site Master™ and a second lower frequency reflectometer (50) such as the model S820 Site Master™, both the S331 and S820 being manufactured by Anritsu Company of Morgan Hill Calif. The high frequency reflectometer (150) includes a forward coupler (109) having a coupling path connected to a high frequency impulse signal source (102), and a through path connecting the test port (3) and incident and reflected signal measurement couplers (110,112) to a load (107). To connect the high and low frequency reflectometers (150,50), a diplexer (170) is connected between the load (107) and an output of the low frequency reflectometer (50).

Abstract: A method and apparatus are used to calibration a Vector Network Analyzer (VNA). The method includes providing a calibration module with a single port, providing within the calibration module a set of reflecting components with known scattering parameters, providing control signals to the calibration module through the single port, providing the known scattering parameters to the VNA through the single port, coupling one of reflecting components to the VNA, measuring scattering parameters, and comparing the measured scattering parameters with the known scattering parameters. The apparatus includes a calibration module and a controller module. In one embodiment, the calibration module includes a set of reflecting components, a memory that stores the characterization data, and a current source which sends characterization data in the form of current pulses to the controller module. The controller module includes a voltage source that generates the control signals used by the calibration module.

Abstract: A method and apparatus are used to calibration a Vector Network Analyzer (VNA). The method includes providing a calibration module with a single port, providing within the calibration module a set of reflecting components with known scattering parameters, providing control signals to the calibration module through the single port, providing the known scattering parameters to the VNA through the single port, coupling one of reflecting components to the VNA, measuring scattering parameters, and comparing the measured scattering parameters with the known scattering parameters. The apparatus includes a calibration module and a controller module. In one embodiment, the calibration module includes a set of reflecting components, a memory that stores the characterization data, and a current source which sends characterization data in the form of current pulses to the controller module. The controller module includes a voltage source that generates the control signals used by the calibration module.

Abstract: A graph of data samples in a graph field on the display, including a first coordinate axis, a second coordinate axis, a trace indicating characteristics of data samples with respect to the coordinate axes, and a plurality of markers indicating positions of respective data samples along the trace is displayed. The markers appear on the display in the form of a symbol and a marker annotation field and are positioned within the graph field adjacent the data sample to which they are tied. The positions of the marker fields of the plurality of markers are calculated according to a preferred orientation with respect to the trace and their respective data samples. Markers are identified for which the marker annotation field according to the calculated position, lie in whole or in part outside the graph field, or for which the marker annotation field overlaps a marker field of another marker in the plurality of markers.