High bandwidth oscilloscope for digitizing an analog signal having a bandwidth greater than the bandwidth of digitizing components of the oscilloscope

A method for digitizing an analog signal spanning a frequency range, comprising the steps of:

• digitizing a first portion of the analog signal spanning a first portion of the frequency range into a first signal occupying a first frequency band;
• translating a second portion of the analog signal spanning a second portion of the frequency range, at least a part of the second portion of the frequency range overlapping a part of the first portion of the frequency range, to a lower frequency band corresponding to a lower frequency portion of the frequency range;
• digitizing the translated second portion of the analog signal with digitizing elements having a frequency range less than the analog signal frequency range to form a digitized translated second signal;
• translating a third portion of the analog signal spanning a third portion of the frequency range, at least a part of the third portion of the frequency range overlapping a part of the second portion of the frequency range, to a lower frequency band corresponding to a lower frequency portion of the frequency range;
• digitizing the translated third portion of the analog signal with digitizing elements having a frequency range less than the analog signal frequency range to form a digitized translated third signal;
• forming a digital representation of the analog signal from the digitized first signal, the digitized translated second signal, and the digitized translated third signal, wherein the digital representation is a substantially accurate representation of the analog signal across substantially the entire frequency range of the analog signal;
• and
• storing the digital representation in a computer readable medium.

A system for acquiring an analog signal, comprising:

• an analog input to receive an analog signal spanning a frequency range, a first portion of the analog signal spanning a first frequency band of the frequency range, a second portion of the analog signal spanning a second frequency band of the frequency range, and a third portion of the analog signal spanning a third frequency band of the frequency range, at least a portion of said second frequency band being higher than said first frequency band and at least a portion of said second frequency band overlapping said first frequency band, at least a portion of said third frequency band being higher than said second frequency band and at least a portion of said third frequency band overlapping said second frequency band;
• a first signal path to transport the first portion of the analog signal occupying the first frequency band;
• a second signal path to transport the second portion of the analog signal occupying the second frequency band;
• a third signal path to transport the second portion of the analog signal occupying the second frequency band;
• a first frequency translator to translate the second portion of the analog signal to a lower frequency band;
• a second frequency translator to translate the third portion of the analog signal to a lower frequency band;
• a digitizing system to digitize the first portion of the analog signal, the second portion of the analog signal, and the third portion of the analog signal to form a digitized first signal, a digitized second signal, and a digitized third signal, the digitizing system having a frequency range less than the analog signal frequency range;
• a third frequency translator for substantially restoring the digitized second signal to the second frequency band;
• a fourth frequency translator for substantially restoring the digitized third signal to the third frequency band;
• and
• a digital combiner to join the digitized first signal, the digitized second signal and the digitized third signal to form a digital representation of the analog signal, the digital representation substantially spanning the frequency range of the analog signal.

A system for acquiring an analog signal, comprising:

• an analog input to receive an analog signal spanning a frequency range, a first portion of the analog signal spanning a first frequency band of the frequency range, a second portion of the analog signal spanning a second frequency band of the frequency range;
• a first signal path to transport the first portion of the analog signal occupying the first frequency band;
• a second signal path to transport the second portion of the analog signal occupying the second frequency band;
• a digitizing system to digitize the first portion of the analog signal and the second portion of the analog signal, to form a digitized first signal and a digitized second signal;
• and
• a digital combiner to join the digitized first signal and the digitized second signal to form a digital representation of the analog signal, the digital representation substantially spanning the first and second frequency bands of the frequency range of the analog signal.

A method for acquiring an analog signal, comprising:

• receiving an analog signal spanning a frequency range, a first portion of the analog signal spanning a first frequency band of the frequency range, a second portion of the analog signal spanning a second frequency band of the frequency range;
• digitizing the first portion of the analog signal and the second portion of the analog signal, to form a digitized first signal and a digitized second signal;
• and
• joining the digitized first signal and the digitized second signal to form a digital representation of the analog signal, the digital representation substantially spanning the first and second frequency bands of the frequency range of the analog signal.