Pulse generator

A method of generating a pulse comprising:

• activating a plurality of switching elements of a first signal generating arm in a predetermined sequence so as to draw current through a first inductor of the first signal generating arm and thereby generating a predetermined pulse waveform at a pulse generator output, wherein:
• the plurality of switching elements in the first signal generating arm are arranged to draw different amounts of current;
• and
• the plurality of switching elements have different current drawing capabilities to generate peaks and troughs at the pulse generator output of different amplitude;
• and
• wherein the predetermined sequence is arranged to create an approximate Gaussian derivative pulse shape.

A pulse generator comprising:

• a first signal generating arm comprising a first inductor and a plurality of switching elements, each arranged to draw current through the first inductor;
• and
• a controller arranged to activate the plurality of switching elements in a predetermined sequence so as to generate a predetermined pulse waveform at a pulse generator output, wherein;
• the plurality of switching elements in the first signal generating arm are arranged to draw different amounts of current, and;
• the plurality of switching elements have different current drawing capabilities to generate peaks and troughs at the pulse generator output of different amplitude;
• wherein the controller comprises a multiphase clock that generates a clock signal at a plurality of different phases, and wherein the different phases are arranged to drive the switching elements;
• wherein each switching element is provided with enable logic that determines its activation and deactivation based on one or more clock phase signals;
• wherein the enable logic comprises a polarity input arranged to select between two opposite pulse polarities;
• the pulse generator further comprising a second signal generating arm comprising a second inductor and a plurality of switching elements, each arranged to draw current through the second inductor;
• wherein the enable logic is arranged to trigger switching elements of the first signal generating arm and second signal generating arm alternately and wherein the polarity input is arranged to swap the alternation pattern;
• wherein the enable logic comprises a multiplexer which takes a plurality of clock phases as inputs and outputs one or more clock phases selected from among said inputs, and wherein the polarity input provides the select input to the multiplexers so as to switch the timing of the switching elements;
• and
• wherein the polarity input is provided directly to one of the first and second signal generating arms and is inverted before being applied to the other of the first and second signal generating arms.

A pulse generator comprising:

• a first signal generating arm comprising a first inductor and a plurality of switching elements, each arranged to draw current through the first inductor;
• and
• a controller arranged to activate the plurality of switching elements in a predetermined sequence so as to generate a predetermined pulse waveform at a pulse generator output, wherein;
• the plurality of switching elements in the first signal generating arm are arranged to draw different amounts of current, and;
• the plurality of switching elements have different current drawing capabilities to generate peaks and troughs at the pulse generator output of different amplitude;
• the pulse generator further comprising a second signal generating arm that comprises a second inductor and a plurality of switching elements, each arranged to draw current through the second inductor;
• wherein the first inductor and the second inductor are formed from a single center-tapped inductor.