Method For Carrying Out A Frequency Change
AssigneeRohde & Schwarz GmbH & Co. KG
InventorGeorg Ortler
Life of this patent
Estimating the term…
Abstract
The invention relates to a method for carrying out a frequency change whilst retaining the phase relationship between several devices, in particular, network analyzers. Each device has at least one signal generator for stimulating an object for measurement and at least one local oscillator, connected to at least one mixer, for receiving a measuring signal obtained from the object for measurement by the superposition principle. On changing frequency, in a first step, only the frequency of the local oscillators of all devices is changed and the frequency of the signal generators of all devices remains unchanged. In a second step, only the frequency of at least one signal generator is changed and the frequency of the local oscillators of all devices remains unchanged.
Claims6
Method for the implementation of a frequency change while retaining the phase relationship between several devices wherein each device provides at least one signal generator for the excitation of a device under test and at least one local oscillator connected to at least one mixer for the reception of a test signal obtained from the device under test according to the superposition principle,
- comprising
- in the event of a frequency change, in a first stage, initially varying only the frequency of the local oscillators of all devices, and maintaining the frequency of the signal generators of all devices remains unchanged;
- and in a second stage, varying only the frequency of at least one signal generator of at least one device, and maintaining the frequency of the local oscillators of all devices unchanged or that,
- in the event of the frequency change, in a first stage, initially varying only the frequency of at least one signal generator of at least one device, and maintaining the frequency of the local oscillators of all devices unchanged;
- and in a second stage, varying only the frequency of the local oscillators of all devices, and maintaining the frequency of the signal generators of all devices unchanged.
Method according to,
- wherein
- each local oscillator and each signal generator provides at least one phase-locked loop with at least one divider, which implements a frequency division by a fractional-rational division factor;
- comprising
- in the event of a rough frequency change, initially varying the integer component of the division factor of each local oscillator and of at least one signal generator;
- and,
- in the event of a subsequent fine frequency change, in a first stage, initially varying only the non-integer component of the division factor of each local oscillator, and maintaining the non-integer component of the division factor of the at least one signal generator unchanged;
- and in a second stage, varying only the non-integer component the division factor of the at least one signal generator, and maintaining the non-integer component of the division factor of all local oscillators unchanged, or,
- in the event of a subsequent fine frequency change, in a first stage, initially varying only the non-integer component of the division factor of the at least one signal generator, and maintaining the non-integer component of the division factor of all local oscillators unchanged;
- and in a second stage, varying only the non-integer component the division factor of every local oscillator, and maintaining the non-integer component of the division factor of the at least one signal generator unchanged.
Dependencies are inferred from the claim text.