System and method of creating periodic pulse sequences with defined absolute phase

Abstract

A system to create periodic pulse sequences with defined absolute phase comprises a phase coherent analyzer and a pulse generator. The phase coherent analyzer and the pulse generator are connected with each other. The pulse generator has a clock input connected to the analyzer for receiving a clock signal from the analyzer. The system comprises a trigger line via which a marker signal is provided to at least one of the analyzer and the pulse generator. The marker signal temporally aligns an output signal of the pulse generator with a measurement process of the analyzer. Further, a method of creating periodic pulse sequences with defined absolute phase is described.

Claims

1. A system to create periodic pulse sequences with defined absolute phase, the system comprising a phase coherent analyzer and a pulse generator, the phase coherent analyzer and the pulse generator being connected with each other, the pulse generator having a clock input connected to the analyzer for receiving a clock signal from the analyzer, the system comprising a trigger line via which a marker signal is provided to at least one of the analyzer and the pulse generator, the marker signal temporally aligning an output signal of the pulse generator with a measurement process of the analyzer such that the system is a coherent one that is configured to create periodic pulse sequences with defined absolute phase.

2. The system according to claim 1, wherein the pulse generator has a periodic sequence that defines on which cycles of the clock signal the pulse generator generates a pulse.

3. The system according to claim 2, wherein the periodic sequence is either pre-set or configurable by a user.

4. The system according to claim 2, wherein the periodic sequence relates to a divider mode, a pseudo random binary sequence mode or a custom periodic sequence mode.

5. The system according to claim 1, wherein the marker signal is an analyzer marker signal issued from the analyzer, the analyzer marker signal internally synchronizing at least one measurement process of the analyzer.

6. The system according to claim 1, wherein the pulse generator is configured to receive the marker signal and to compare the marker signal to the clock signal.

7. The system according to claim 1, wherein the marker signal corresponds to a trigger signal issued from the pulse generator.

8. The system according to claim 1, wherein the analyzer is configured to receive the marker signal from the pulse generator.

9. The system according to claim 1, wherein the marker signal is provided by an external device.

10. The system according to claim 1, wherein the pulse generator is a comb generator.

11. The system according to claim 1, wherein the pulse generator and the analyzer are integrated in a common device.

12. A method of creating periodic pulse sequences with defined absolute phase, with the following steps: Establishing a connection between an analyzer and a pulse generator, Providing a clock signal from the analyzer to the pulse generator, Establishing a trigger line to at least one of the analyzer and the pulse generator, and Providing a marker signal that temporally aligns an output signal of the pulse generator with a measurement process of the analyzer in order to create periodic pulse sequences with defined absolute phase.

13. The method according to claim 12, wherein the pulse generator receives the marker signal and the pulse generator compares the marker signal to the clock signal.

14. The method according to claim 12, wherein the marker signal is an analyzer marker signal issued from the analyzer, the analyzer marker signal internally synchronizing at least one measurement process of the analyzer.

15. The method according to claim 12, wherein the marker signal corresponds to a trigger signal issued from the pulse generator.

16. The method according to claim 12, wherein the analyzer receives the marker signal from the pulse generator.

17. The method according to claim 12, wherein the analyzer is temporally aligned in post-processing.

18. The method according to claim 12, wherein the marker signal is provided by an external device.

19. A system to create periodic pulse sequences with defined absolute phase, the system comprising a phase coherent analyzer and a pulse generator, the phase coherent analyzer and the pulse generator being connected with each other, the pulse generator having a clock input connected to the analyzer for receiving a clock signal from the analyzer, the system comprising a trigger line via which a marker signal is provided to at least one of the analyzer and the pulse generator, the marker signal temporally aligning an output signal of the pulse generator with a measurement process of the analyzer, and wherein the marker signal corresponds to an electrical pulse that relates to a direct alignment, an alignment with a predefined delay or rather an alignment that depends on the clock signal.

Description

DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 schematically shows a system according to an embodiment of the present disclosure,

(3) FIG. 2 shows an overview illustrating signals over time without temporal alignment,

(4) FIG. 3 shows the overview of FIG. 2 with temporal alignment, and

(5) FIG. 4 schematically shows another embodiment of a system according to the present disclosure.

DETAILED DESCRIPTION

(6) The detailed description set forth below in connection with the appended drawings, where like numerals reference like elements, is intended as a description of various embodiments of the disclosed subject matter and is not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the claimed subject matter to the precise forms disclosed.

(7) In FIG. 1, a system 10 is shown that comprises an analyzer 12 and a pulse generator 14 that are connected with each other.

(8) The analyzer 12 and the pulse generator 14 may be integrated in a common device 15 or rather formed separately. Both alternatives are illustrated in FIG. 1, as both positions of the pulse generator 14 are illustrated by dashed lines.

(9) The analyzer 12 has a signal output 16, for instance a radio frequency output, via which a radio frequency signal such as a continuous wave signal is output, which is forwarded to the pulse generator 14. The respective signal is received by the pulse generator 14 while being used as a clock signal. Hence, the pulse generator 14 has a clock input 17 that is connected to the signal output 16 of the analyzer 12.

(10) Further, the pulse generator 14 is connected to the analyzer 12 by a trigger line 18 via which a marker signal is exchanged between the analyzer 12 and the pulse generator 14. Hence, the analyzer 12 as well as the pulse generator 14 each have a respective trigger interface 19, 20 via which the analyzer 12 and the pulse generator 14 are also interconnected with each other.

(11) Accordingly, the trigger line 18 is part of the system 10, wherein the trigger line 18 is used to transmit the marker signal as will be described later in more detail.

(12) In addition, the pulse generator 14 has an output 21 via which an output signal is issued that is forwarded to an input 22 of the analyzer 12. The output signal of the pulse generator 14 corresponds to a periodic output sequence.

(13) Hence, the pulse generator 14 has a periodic sequence that defines on which cycles of the clock signal received the pulse generator 14 generates a pulse. This is inter alia shown in FIG. 2 illustrating the radio frequency input signal (RF input signal) as well as the resulting clock signal.

(14) Generally, the periodic sequence of the pulse generator 14 may be assigned to a divider mode, a pseudo random binary sequence mode or a custom periodic sequence mode. In the example shown in FIG. 2, the periodic sequence relates to a divider mode (N=2). In fact, the frequency spacing of the pulses is given by half of the frequency of the clock signal.

(15) As shown in FIG. 2, the output signal of the pulse generator 14, namely the periodic output sequence, may have two possible states with 180 phase shift. Hence, a 180 phase shift between the measured spectra of both divider output signals occur depending on the respective starting point of the periodic sequence of the pulse generator 14. This is also called phase ambiguity.

(16) Accordingly, absolute phase calibration is not possible due to the phase ambiguity.

(17) In order to overcome this drawback, the marker signal exchanged via the trigger line 18 is used that synchronizes the pulse generator 14 with the analyzer 12 in time (temporal alignment).

(18) In other words, the output signal of the pulse generator 14 is temporally aligned with an internal measurement process of the analyzer 12.

(19) Accordingly, an absolute phase calibration can be employed by the system 10, as a phase ambiguity in the spectrum of the output signal of the pulse generator 12 is eliminated due to the marker signal exchanged.

(20) Thus, the system 10 is configured to create periodic pulses, namely the output signal of the pulse generator 14, with defined absolute phase. In other words, a coherent system 10 is provided.

(21) According to a first embodiment, an analyzer marker signal provided by the analyzer 12 is forwarded via the trigger line 18 from the analyzer 12 to the pulse generator 14, which serves as the marker signal. The analyzer marker signal temporally aligns the pulse generator 14 with the analyzer 12.

(22) In fact, the output signal, particularly the periodic output sequences, of the pulse generator 14 is synchronized with a measurement protocol of the analyzer 12, as the analyzer marker signal is typically used to internally synchronize the measurement processes of the analyzer 12.

(23) Put another way, the analyzer marker signal is typically used to trigger the start and stop of partial measurements of the analyzer 12 internally.

(24) Hence, synchronicity between the analyzer 12 and the pulse generator 14 is established by feeding the analyzer marker signal to the pulse generator 14, which triggers the start and stop of the partial measurement(s) of the analyzer 12. The analyzer marker signal is used to reset the start of the output signal of the pulse generator 14 as shown in FIG. 3. Hence, the output signal of the pulse generator 14 is reset after a certain period of time indicated by T.

(25) This way, the phase ambiguity of the spectrum of the pulse generator 14 can be eliminated, which becomes obvious when comparing the overviews shown in FIGS. 2 and 3.

(26) Accordingly, an input trigger for the pulse generator 14 is introduced via the trigger line 18. The input trigger is received by the pulse generator 14 in order to reset the starting point of the periodic (output) sequence of the pulse generator 14.

(27) Generally, the marker signal established by the analyzer marker signal allows synchronization of the pulse generator 14 with the analyzer 12 in order to temporally align the pulse generator 14 with the analyzer 12, particularly the start of the partial measurement process done by the analyzer 12.

(28) In contrast, as mentioned above, if the start of the output sequence of the pulse generator 14 is not temporally aligned with the analyzer 12, the phase of the spectrum of the output signal of the pulse generator 14 is ambiguous in a divider mode or rather pseudo random binary sequence mode as shown in FIG. 2.

(29) In the example shown in FIG. 2, the output sequence of the pulse generator 14 is half the frequency of the radio frequency signal used as the clock signal while providing a clock frequency for the pulse generator 14. Depending on the temporal start of the output sequence of the pulse generator 14 with respect to the clock signal, there are two possible states with a phase shift of 180 . This is generally known as phase ambiguity.

(30) In order to avoid this phase ambiguity shown in FIG. 2, the marker signal, namely a short electrical pulse, is used to synchronize the analyzer 12 and the pulse generator 14.

(31) The pulse generator 14 that receives the marker signal, particularly the analyzer marker signal, is configured to compare the marker signal received to the clock signal received, particularly to time of edges or rather skirts of the clock signal.

(32) In another embodiment, the marker signal may also correspond to a trigger signal that is issued by the pulse generator 14.

(33) Thus, the marker signal is provided by the pulse generator 14 and forwarded to the analyzer 12 for temporally aligning the analyzer 12 and the pulse generator 14. Hence, the analyzer 12 is configured to receive the trigger signal in order to synchronize its internal measurement process appropriately.

(34) The trigger signal may indicate a reset, namely a beginning, of a periodic sequence of the pulse generator 14, which is used to synchronize the internal measurement process(es) of the analyzer 12 in order to temporally align the analyzer 12 and the pulse generator 14.

(35) For instance, the analyzer 12 is temporally aligned in post-processing.

(36) In an alternative embodiment shown in FIG. 4, the marker signal is provided by an external device 24. The external device 24 may input the marker signal to the analyzer 12 and/or the pulse generator 14.

(37) The analyzer 12 or rather the pulse generator 14 may forward the marker signal received from the external device 24 to the other component of the system 10 in order to establish a further trigger line 18 between the analyzer 12 and the pulse generator 14.

(38) For instance, the external device 24 issues the marker signal that is forwarded to the analyzer 12 which in turn forwards the maker signal to the pulse generator 14.

(39) Alternatively, the external device 24 issues the marker signal that is forwarded to the pulse generator 14 which in turn forwards the maker signal to the analyzer 12.

(40) In another alternative, the external device 24 forwards the marker signal to the analyzer 12 and the pulse generator 14 simultaneously in order to synchronize both components of the system 10 without any (direct) interaction between the analyzer 12 and the pulse generator 14 for temporal alignment purposes.

(41) These different alternatives are all indicated in FIG. 4, as the respective trigger lines 18 established between the analyzer 12, the pulse generator 14 and the external device 24 are illustrated by dashed lines.

(42) As described with reference to FIG. 1, the pulse generator 14 and the analyzer 12 may also be housed in a common device such that they are encompassed by a common housing.

(43) Generally, the pulse generator 14 may be established by a comb generator. The analyzer 12 may be a vector network analyzer or rather a spectrum analyzer.

(44) As mentioned above, the pulse generator 14 has a periodic sequence that defines on which cycles of the clock signal received, the pulse generator 14 generates a pulse. Hence, the pulse generator 14 does not necessarily have to generate a pulse on every edge provided by the clock signal.

(45) The periodic sequence used may be pre-set and/or configurable by a user of the system 10. Thus, a default value for the periodic sequence may be set. However, the default value can be used or rather overwritten by a user if desired. Thus, the periodic sequence may relate to a divider sequence (divider mode), a pseudo random binary sequence (PRBS mode) or a custom periodic sequence (custom periodic mode).

(46) In general, the system 10 ensures that a pulse generator 14 for arbitrary periodic output sequences is provided, which is synchronized in time with the analyzer 12. In fact, the periodic output sequence of the pulse generator 14 is reset at a well-defined time with respect to the radio frequency input signal, namely the clock signal received. This allows to resolve any phase ambiguity of the output signal, namely the periodic output sequence. Hence, periodic output sequences can be used in a coherent manner. Thus, an absolute phase calibration can be employed by the system 10 due to the trigger line 18 established in the system 10 that temporally aligns the analyzer 12 and the pulse generator 14.