Ronald C Potter

US Patent:

45874778, May 6, 1986

Filed:

May 18, 1984

Appl. No.:

6/611803

Inventors:

Thomas Hornak - Portola Valley CA
Gary L. Baldwin - Palo Alto CA
Ronald W. Potter - Saratoga CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G05F 316

US Classification:

323312

Abstract:

A binary scaled current source in which a set of binary switches M. sub. 1,. . . , M. sub. n controllably switch a current I to a selected one of a set of n outputs. Each switch M. sub. k is controlled by an associated control signal B. sub. k having a duty cycle of 2. sup. k-n-1. At any given time one and only one of the control signals is high so that the current I is diverted to the kth output a fraction 2. sup. k-n-1 of the time. In two particular schemes referred to as the weighted pulse width (WPW) and the weighted repetition rate (WRR) schemes, all of the control signals are periodic with a group pattern repetition period T. In the WPW scheme, B. sub. k has in each period T a single pulse of duration 2. sup. k-n-1 *T. In the WRR scheme, B. sub. k has in each period T2. sup.

US Patent:

46583670, Apr 14, 1987

Filed:

Aug 23, 1984

Appl. No.:

6/644405

Inventors:

Ronald W. Potter - Saratoga CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1520
G06F 1100
H03F 1266

US Classification:

364553

Abstract:

A pole and zero analyzer determines the poles and zeroes of a device for applying a stimulus signal to the device, detecting the stimulus and response signals and computing the auto- and cross spectra. An estimated transfer function is least squares fit to a measured transfer function obtained from the auto- and cross-spectra and the poles and zeroes are obtained as the roots of the estimated transfer function. Inaccuracies due to noise are minimized by subtracting out a noise bias from the squared cross-spectrum obtained during the least squares fit and by orthogonalizing a data matrix used in the determination of the coefficients of the estimated transfer function.

US Patent:

43170927, Feb 23, 1982

Filed:

Jun 30, 1980

Appl. No.:

6/164411

Inventors:

Ronald W. Potter - Saratoga CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

H03H 1704
H03H 1112

US Classification:

333165

Abstract:

A recursive digital low-pass filter processes an input signal with essentially unity gain and sharp frequency cutoff without using multipliers to provide an output signal with an information bandwidth substantially one-half that of the input signal.

US Patent:

44244924, Jan 3, 1984

Filed:

Feb 8, 1982

Appl. No.:

6/347113

Inventors:

Ronald W. Potter - Saratoga CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

H03K 500
H03L 700

US Classification:

328155

Abstract:

A frequency converter for a complex digital input provides a shift of frequency without the necessity of time-consuming and expensive numerical multiplication. Furthermore, by combining the conversion process with digital filtering, the frequency of the converted output can be halved. The output can be resampled and reapplied to the novel converter for repeated shifts in frequency and reduction of bandwidth in the case of down-conversion.

US Patent:

46548084, Mar 31, 1987

Filed:

Aug 23, 1984

Appl. No.:

6/644404

Inventors:

Ronald W. Potter - Saratoga CA
James L. Adcock - Marysville WA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1520
G06F 1100
H03F 1266

US Classification:

364553

Abstract:

A pole and zero analyzer determines the poles and zeroes of a device by applying a stimulus signal to the device, detecting the stimulus and response signals and computing the auto- and cross-spectra. An estimated transfer function is least squares fit to a measured transfer function obtained from the auto- and cross-spectra and the poles and zeroes are obtained as the roots of the estimated transfer function. A weighting function may be used to emphasize certain desired regions of the frequencies of interest in the determination of the least squares fit. The orders of the poles and zeroes are modified until an optimum fit is reached.