Abstract: A method and apparatus for continuous RF signal visualization with high resolution acquires RF signal data within a specified frequency bandwidth seamlessly to produce digitized time domain data. The digitized time domain data is processed in both the frequency and time domains to form high resolution spectral and time traces which are stored. To match human visualization abilities, the high resolution traces are combined to form low resolution traces which are displayed. With the spectral traces, spectrum bitmaps may be generated and stored so that the spectrum bitmap for any displayed spectral trace may be recalled and displayed. The high resolution traces for any specified low resolution trace may be recalled for display. Finally multiple trigger event types may be generated and displayed with the displayed traces.

Abstract: A method and apparatus for continuous RF signal visualization with high resolution acquires RF signal data within a specified frequency bandwidth seamlessly to produce digitized time domain data. The digitized time domain data is processed in both the frequency and time domains to form high resolution spectral and time traces which are stored. To match human visualization abilities, the high resolution traces are combined to form low resolution traces which are displayed. With the spectral traces, spectrum bitmaps may be generated and stored so that the spectrum bitmap for any displayed spectral trace may be recalled and displayed. The high resolution traces for any specified low resolution trace may be recalled for display. Finally multiple trigger event types may be generated and displayed with the displayed traces.

Abstract: A “density trace” according to an embodiment of the present invention is formed by measuring the density of each column of a frequency domain bitmap above a user-specified “amplitude threshold.” The density of each column equals the sum of the densities of all of the pixels in the column that are above the amplitude threshold divided by the sum of the densities of all of the pixels in the column. A density trace provides a convenient way to define and represent the occupancy for a large number of columns, and also allows density data to be quickly transmitted from one instrument or computer to another. In some embodiments, a density trace is incorporated into a trigger detector of a test and measurement instrument and used to generate a trigger signal. The trigger detector compares the density trace to a user-specified “density threshold” and generates the trigger signal when the value of any point of the density trace violates the density threshold.

Abstract: A method and apparatus for continuous RF signal visualization with high resolution acquires RF signal data within a specified frequency bandwidth seamlessly to produce digitized time domain data. The digitized time domain data is processed in both the frequency and time domains to form high resolution spectral and time traces which are stored. To match human visualization abilities, the high resolution traces are combined to form low resolution traces which are displayed. With the spectral traces, spectrum bitmaps may be generated and stored so that the spectrum bitmap for any displayed spectral trace may be recalled and displayed. The high resolution traces for any specified low resolution trace may be recalled for display. Finally multiple trigger event types may be generated and displayed with the displayed traces.

Abstract: Embodiments of the present invention provide a test and measurement instrument that displays acquired data on a logarithmic scale without intensity banding. The test and measurement instrument processes the acquired data before it is displayed by appending pseudo-random sub-LSB (least significant bit) values to it. When the processed acquired data is displayed on a logarithmic scale, the pseudo-random sub-LSB values fill in the gaps between discrete power levels, thereby eliminating intensity banding and providing a smooth, visually pleasing display.

Abstract: Embodiments of the present invention provide a test and measurement instrument that processes acquired data before it is displayed by re-sampling it with a pseudo-random sampling phase. This data processing step introduces a randomly-varying phase between the signal under test and the sampling clock of the test and measurement instrument, thereby canceling the effect of any synchronization between the two. In this manner, the test and measurement instrument may acquire data based on a clock signal that is very close to, or even synchronized with, the test and measurement instrument's own sampling clock (or a harmonic of it), and yet still provide a smooth, artifact-free display.

Abstract: A “density trace” according to an embodiment of the present invention is formed by measuring the density of each column of a frequency domain bitmap above a user-specified “amplitude threshold.” The density of each column equals the sum of the densities of all of the pixels in the column that are above the amplitude threshold divided by the sum of the densities of all of the pixels in the column. A density trace provides a convenient way to define and represent the occupancy for a large number of columns, and also allows density data to be quickly transmitted from one instrument or computer to another. In some embodiments, a density trace is incorporated into a trigger detector of a test and measurement instrument and used to generate a trigger signal. The trigger detector compares the density trace to a user-specified “density threshold” and generates the trigger signal when the value of any point of the density trace violates the density threshold.

Abstract: A test set used for introducing a Poisson distribution of errors into a known digital data signal to produce a test signal uses an error signal generator that produces a Poisson distribution error signal. The error signal is then combined with the known digital data signal to produce a test signal with the Poisson distribution of errors. A pseudo-random binary sequence generator is used to produce a PRBS sequence and a comparator is used for comparing the PRBS sequence with a probability control signal. The comparator sets a single bit in the output stream of zeros when the PRBS sequence is less than the probability control signal. For multiple bit Poisson distribution error signals the PRBS generator and comparator combination may be replicated m times, or a single PRBS generator may be used and a unique independent subset of the PRBS sequence is applied to each of the multiple comparators.

Abstract: A test set used for introducing a Poisson distribution of errors into a known digital data signal to produce a test signal uses an error signal generator that produces a Poisson distribution error signal. The error signal is then combined with the known digital data signal to produce a test signal with the Poisson distribution of errors. A pseudo-random binary sequence generator is used to produce a PRBS sequence and a comparator is used for comparing the PRBS sequence with a probability control signal. The comparator sets a single bit in the output stream of zeros when the PRBS sequence is less than the probability control signal. For multiple bit Poisson distribution error signals the PRBS generator and comparator combination may be replicated m times, or a single PRBS generator may be used and a unique independent subset of the PRBS sequence is applied to each of the multiple comparators.

Abstract: A synchronous programmable binary counter has a parallel section and a serial section, with the length (in bits) of the serial section being the same as the modulus of the parallel section. The parallel section counts on system clocks and produces two outputs. A parallel terminal count output is produced each time the parallel section count reaches a programmed value. A frame output is generated every time the parallel section reaches its maximum count and starts counting again. The serial counter section decrements its programmed value by one each time it receives a frame signal from the parallel section. This subtraction is accomplished by a half-adder and associated borrow flip-flop. The borrow flip-flop is set by each arrival of the frame signal. Between frame signals, the decremented programmed value is circulated in a shift register as the serial subtraction process is performed.

Abstract: An oscilloscope displays a menu consisting of set of field codes and one configuration code set grouped with each field code. Each field code represents an oscilloscope operating parameter while each configuration code represents an alternative oscilloscope operating mode associated with the operating parameter. A configuration cursor is displayed underlining one configuration code in each field thereby indicating the current operating configuration of the oscilloscope. The configuration of the oscilloscope may be changed by first rotating a first control knob, mounted on the oscilloscope front panel, to locate a field selection cursor under a selected field code and then by rotating a second control knob to move the associated configuration cursor under the desired configuration code. The configuration of each field may be altered by selective operation of the two control knobs in this manner.

Abstract: A binary ripple counter having exclusive OR coupling elements between the counter bistables for use in a digital delay by events circuit of a display device such as an oscilloscope. The counter is programmable.