Tektronix, Inc.

Cascade Microtech, Inc.

Trisys, Inc.

Larry R Lockwood

Eric W Strid

Linley F Gumm

Xiaofen Chen

H Erwin Grellmann

Leonard A Roland

Kimberly R Gleason

Dana E Whitlow

A system and method for in-service transmitter phase noise measurements determines phase nonlinearity by way of comparing unfiltered signal samples and regenerated reference signal samples to calculate phase nonlinearity error. Linear distortion is removed from the received signal samples in order to truly characterize nonlinear behavior of the transmitter. The unfiltered signal samples are generated without applying the receiver shaping filtering. Reference signal samples are regenerated from estimated transmitted symbols derived from the unfiltered signal samples. The transmitted symbols are estimated using a segmented slicer which dynamically estimates constellation decision levels from the unfiltered signal samples. A weighted, least-square based polynomial regression is performed on phase error samples of the unfiltered signal samples to estimate a phase nonlinear error function while suppressing the impact of other non-systematic distortions. The nonlinear phase error is removed from the phase error to produce phase noise containing carrier phase jitter and additive noise. A threshold is determined for replacing phase error values outside the threshold with random values having a distribution equivalent to the carrier phase jitter. The carrier phase jitter may be displayed as a power spectrum of the phase noise.

Measurement test set and method for in-service measurements of phase noise

An electrostatic discharge testing device employs magnetic reed relays in a switching array for selectively routing high-voltage, fast rise-time signals. The contacts of the reed relays are copper plated to minimize skin effect and thus decrease rise-time. Interposed between the glass enclosure and the magnetic coil of each reed relay is a metal-plated dielectric sheet formed in a tube with the plated side facing out. The plating at each end of the tube is connected to a ground reference voltage via a resistor.

Electrostatic discharge testing device

A wafer probe is provided having metallic transmission lines mounted on a tapered alumina substrate generally surrounded by microwave absorbing material. The probe provides for on-wafer measurements of small planar devices at frequencies from DC to at least 18 GHz with low inductance, and with constant characteristic impedance from the probe external cable terminal to the point of contact on device being probed. The microwave absorbing material absorbs energy propagating along the probe ground preventing this energy from resonating, radiating and re-exciting normal transmission line modes with minimal transmission line mode resonance along the probe ground. The probe, which may be coupled to receive signals from a coaxial cable, is capable of making contact with bonding pads of a device having a center-to-center distance between pads of only 4 mils.

Wafer probe

A broad band, thin film attenuator for microwave circuits is constructed by placing a ground plane conductor on one side of a ceramic, insulating substrate, and conductive, resistive, and reactive elements on the other side of the substrate. Capacitive stubs are provided to compensate for inductance in grounding conductors between resistance elements and the ground plane conductor. Constrictions are provided in input and output conductors to provide increased series inductance to compensate for distributed capacitance of the resistance elements. One resistance element is constructed so that the interface between the input conductor and that resistance element forms an obtuse interior angle with an adjoining transitional edge extending from the input conductor to the grounding conductor, and the transitional edge forms an obtuse interior angle with the adjoining edge of the grounding conductor, so as to minimize current density concentrations and distributed capacitance. A second resistance element is employed to achieve additional attenuation.

Broad band, thin film attenuator and method for construction thereof

A phase detector uses the junction of a coplanar waveguide and a slot line. The coplanar waveguide serves as an input terminal and is contiguous to the slot line which is shorted. A strobe pulse is applied to the shorted slot line via a snap-off diode, and an input signal is passed via sampling diodes and capacitors to a common mode output.

Phase detector

A circuit configuration is provided for reducing noise sidebands in the output of an oscillator due to modulation of the oscillation signal by characteristic noise produced by the amplifying element. A gallium arsenide field-effect transistor that produces characteristic noise is operated as a linear amplifier. Positive feedback to the input of the amplifier is provided by a resonator. The amplitude of the oscillation signal is limited by a distinct limiting circuit in the feedback loop, the input to which is isolated from the amplifier by a high pass filter, thereby divorcing the non-linear limiting function of the oscillator from the amplifying function where noise is generated.

Low noise oscillator

A dielectric resonator frequency selective network. A frequency selective network for microwave circuits is provided whereby a dielectric resonator is coupled to associated circuitry by input and output coupling loops formed in a single circuit board. The two loops are closely spaced, but partially overlapping at a position such that they are substantially decoupled from one another. A dielectric resonator is placed adjacent one of the loops so as to couple one loop to the other through the resonator and to cause the resonator to operate in its dominant mode. The circuit board is constructed by forming conductors separated by insulating material on a ceramic substrate.

Dielectric resonator frequency selective network

An electronic filter device comprises a high frequency section and a low frequency section. The high frequency section has an input coupling loop connected to an input connection of the filter device, and a gyromagnetic resonance element. The low frequency section comprises at least one inductor and at least one capacitor connected to the input coupling loop of the high frequency section. The two sections of the filter device have separate output connections.

Growing community of inventors

McMinnville, OR, United States of America

Larry R Lockwood