Vector network analyzer with integral processor

Abstract

A precision vector network analyzer which is suitable for a wide range of applications including both laboratory and automated production measurements and testing is disclosed. New measurement capabilities, greater ease of use, and nearly complete automation are provided. Contributions include fully coordinated communications between subsystem modules; real time, two channel, precision vector measurements with complete, internal error correction; wide frequency capability from RF to millimeter bands; combined time and frequency domain analysis and display; measurements either in the swept or step frequency modes; and user definable test functions and calibration device sets.

Description

BACKGROUND OF THE INVENTION

Formerly, most magnitude and phase vector measurements at microwave frequencies have been performed by network analyzers using techniques such as those described in "Automatic Network Analyzer 8542A, Section IV Network Analyzer Fundamentals", Hewlett-Packard Co. 1969 and in U.S. Pat. No. 4,244,024 issued Jan. 6, 1981 by Marzalek et al. Such vector network analyzers characterize networks, including devices, components, and systems by measuring the magnitude and phase of the network's transmission and reflection coefficients versus frequency. The capability to measure group delay, a special form of transmission and also usable in reflection, is also often incorporated in a vector network analyzer.

In general, a vector network analysis measurement system contains several separate modules. First is an RF source to provide the stimulus to the device under test (DUT). The stimulus normally covers a limited range of frequencies, either in a continuous analog sweep, referred to as the swept mode, in discrete steps, referred to as the step mode, or a single point mode. Second is a signal separation network to route the stimulus to the DUT and provide a means for sampling the energy that is reflected from, or transmitted through, the DUT. Also, energy is sampled from the signal that is incident upon the DUT in order to provide a reference for all relative measurements. Third is a tuned receiver to convert the resulting signals to an intermediate frequency (IF) for further processing. The magnitude and phase relationships of the original signals must be maintained through the frequency conversion to IF to provide usable measurements. Fourth is a detector to detect the magnitude and phase characteristics of the IF signals, and fifth is a display on which to present the measurement results.

To improve measurement accuracy, a set of "standard" devices with known characteristics can be measured by a computer controlled system. From this data, a set of complex equations can be solved to determine a model representing many of the errors associated with the network analyzer process. This model is then stored in the computer and later when unknown devices are measured, the model can be used to separate the actual data from the "raw" measured data to provide enhanced accuracy in the microwave measurement by a process known as vector error correction.

Accuracy enhancement is very important in microwave measurements because even with the best signal generating and separating devices manufactured to state of the art tolerances, relatively large errors still occur as

Claims

1. A device for mounting a front panel of a drawer, said device comprising:

a holding element fastenable to the front panel;

a fastening element to be fixed to a side wall of the drawer;

a hook member extending substantially perpendicular to the front panel and having a first end including means for engaging said holding element;

means for mounting a second end of said hook member for pivotal movement about an axis extending substantially horizontally and parallel to the front panel, and for selectively shifting said hook member and said holding element relative to said fastening element in a direction perpendicularly of the front panel, thereby clamping the front panel in a mounted position;

means, operable between said fastening element and said hook member, for selectively moving said hook member and said holding element laterally relative to said fastening element, and thereby for adjusting the relative horizontal position of the front panel with respect to the drawer; and

means, operable between said fastening element and said hook member, for selectively pivoting said hook member and said holding member about said axis relative to said fastening element, and thereby for adjusting the relative vertical position of the front panel with respect to the drawer.

2. A device as claimed in claim 1, wherein said holding element has therein a vertical slot and a rod extending across said slot, and said means of said first end of said hook member extends into said slot and engages said rod.

3. A device as claimed in claim 2, wherein said means of said first end of said hook member comprises a hook which engages said rod from the bottom thereof, and said hook has an undercut recess to receive and retain said rod.

4. A device as claimed in claim 2, wherein said first end of said hook member fits snugly within said slot.

5. A device as claimed in claim 1, wherein said horizontal adjusting means comprises a side adjustment screw extending parallel to said axis, said side adjustment screw including a portion threaded into said hook member and a portion abutting said fastening element, such that rotation of said side adjustment screw causes movement of said hook member laterally relative to said fastening element.

6. A device as claimed in claim 1, wherein said vertical adjusting means comprises an eccentric rotatably mounted on said hook member and abutting a horizontal abutment of said fastening element, such that rotation of said eccentric causes said hook member to pivot about said axis.

7. A device as claimed in claim 6, wherein said eccentric is positioned between said axis and said horizontal adjusting means.

8. A device as claimed in claim 1, wherein said shifting means comprises a clamping screw threaded into said second end of said hook member and extending through an elongated hole in said fastening element, said clamping screw having an inclined countersunk head engaging a portion of the rim of said hole, such that tightening of said clamping screw causes said inclined head to move along said rim portion, thereby shifting said clamping screw and said hook member in said direction.

9. A device as claimed in claim 1, wherein said fastening element includes flanges extending parallel to the front panel and against which said holding element abuts.

10. A device as claimed in claim 1, wherein said fastening element is welded to the drawer side wall.