Automatic impedance matching apparatus and method

An automatic impedance matching apparatus having an output port coupled to a load, said input and output ports each having a signal line and a ground line, said signal generator having a predetermined characteristic impedance, said apparatus comprising:

• matching means coupled between said input port and output port for matching the impedance of said load to the impedance of said signal generator, said matching means including a first variable reactive component and a second variable reactive component;
• a detection means for generating an amplitude tune signal related to the difference of the voltage waveform amplitude at said input port and the product of said predetermined characteristic impedance and the current waveform amplitude at said input port and for generating a phase tune signal related to the phase difference between the voltage and current waveforms at said input port, said amplitude tune signal increasing as said voltage amplitude increases and decreasing as said current amplitude increases, said phase tune signal being substantially equal to zero when said input voltage and input current waveforms are in phase, said phase tune signal increasing as said input voltage waveform leads said input current waveform and decreasing as said input voltage waveform lags said input current waveform;
• and
• control means responsive to said amplitude and phase tune signals for adjusting the values of said first and second variable reactive components to provide a tuned condition at said input port, said control means including a first adjustment means for modifying the value of said first variable reactive component as a function of said amplitude tune signal, a second adjustment means for modifying the value of said second variable reactive component as a function of said phase tune signal, said control means further comprising a convergence means for directing the adjustments of said first and second variable components, said convergence means comprising:
• means for generating a coarse tolerance standard signal when the magnitude of said amplitude tune signal is less than a predetermined first amplitude tolerance value and the magnitude of said phase tune signal is less than a predetermined first phase tolerance value;
• means for generating a fine tolerance standard signal when the magnitude of said amplitude tune signal is less than a predetermined second amplitude tolerance value and the magnitude of said phase tune signal is less than a predetermined second phase tolerance value, said second amplitude tolerance value being less than said first amplitude tolerance value and said second phase tolerance value being less than said first phase tolerance value;
• means for initially placing said convergence means in a tuning state and for initially enabling said first and second adjustment means;
• means responsive to said fine tolerance standard signal for causing said convergence means to enter a hysteresis state when said convergence means is in said tuning state, said first and second adjustment means being disabled in said hysteresis state;
• and
• means for placing said convergence means in said tuning state and for enabling said first and second adjustment means when said convergence means is in said hysteresis state and said coarse tolerance standard signal is not being generated.

An automatic impedance matching apparatus having an input port coupled to a signal generator and an output port coupled to a load, said input and output ports each having a signal line and a ground line, said signal generator having a predetermined characteristic impedance, said apparatus comprising:

• matching means coupled between said input port and output port for matching the impedance of said load to the impedance of said signal generator, said matching means including a first variable reactive component and a second variable reactive component;
• a detection means for generating an amplitude tune signal related to the difference of the voltage waveform amplitude at said input port and the product of said predetermined characteristic impedance and the current waveform amplitude at said input port and for generating a phase tune signal related to the phase difference between the voltage and current waveforms at said input port, said amplitude tune signal increasing as said voltage amplitude increases and decreasing as said current amplitude increases, said phase tune signal being substantially equal to zero when said input voltage and input current waveforms are in phase, said phase tune signal increasing as said input voltage waveform leads said input current waveform and decreasing as said input voltage waveform lags said input current waveform;
• and
• control means responsive to said amplitude and phase tune signals for adjusting the values of said first and second variable reactive components to provide a tuned condition at said input port, said control means including a first adjustment means for modifying the value of said first variable reactive component as a function of said amplitude tune signal, a second adjustment means for modifying the value of said second variable reactive component as a function of said phase tune signal, said first adjustment means further comprising a step-width control means for adjusting said first variable component in variable increments, said step width control means comprising:
• slope means for generating an amplitude slope signal related to the derivative of said amplitude tune signal with respect to the component value of said first variable component;
• and
• first stepping means for adjusting the component value of said first variable component in increments equal in magnitude to a first predetermined step width when said amplitude slope signal is greater than zero and for adjusting the component value of said first variable component in increments equal in magnitude to a second predetermined step width when said amplitude slope signal is less than zero, said second step width, being smaller than said first step width.

An automatic impedance matching apparatus having an input port coupled to a signal generator and an output port coupled to a load, said input and output ports each having a signal line and a ground line, said signal generator having a predetermined characteristic impedance, said apparatus comprising:

• matching means coupled between said input port and output port for matching the impedance of said load to the impedance of said signal generator, said matching means including a first variable reactive component and a second variable reactive component;
• a detection means for generating an amplitude tune signal related to the difference of the voltage waveform amplitude at said input port and the product of said predetermined characteristic impedance and the current waveform amplitude at said input port and for generating a phase tune signal related to the phase difference between the voltage and current waveforms at said input port, said amplitude tune signal increasing as said voltage amplitude increases and decreasing as said current amplitude increases, said phase tune signal being substantially equal to zero when said input voltage and input current waveforms are in phase, said phase tune signal increasing as said input voltage waveform leads said input current waveform and decreasing as said input voltage waveform lags said input current waveform;
• and
• control means responsive to said amplitude and phase tune signals for adjusting the values of said first and second variable reactive components to provide a tuned condition at said input port, said control means including a first adjustment means for modifying the value of said first variable reactive component as a function of said amplitude tune signal, a second adjustment means for modifying the value of said second variable reactive component as a function of said phase tune signal, said second adjustment means further comprising a step-width control means for adjusting said second variable component in variable increments, said step width control means comprising:
• slope means for generating a phase slope signal related to the derivative of said phase tune signal with respect to the component value of said second variable component;
• and
• first stepping means for adjusting the component value of said second variable component in increments equal in magnitude to a first predetermined step width when said phase slope signal is greater than zero and for adjusting said second variable component in increments equal in magnitude to a second predetermined step width when said phase slope signal is less than zero, said second step width being smaller than said first step width.

An automatic impedance matching apparatus having an input port coupled to a signal generator and an output port coupled to a load, said input and output ports each having a signal line and a ground line, said signal generator having a predetermined characteristic impedance, said apparatus comprising:

• matching means coupled between said input port and output port for matching the impedance of said load to the impedance of said signal generator, said matching means including a first variable reactive component and a second variable reactive component;
• a detection means for generating an amplitude tune signal related to the difference of the voltage waveform amplitude at said input port and the product of said predetermined characteristic impedance and the current waveform amplitude at said input port and for generating a phase tune signal related to the phase difference between the voltage and current waveforms at said input port, said amplitude tune signal increasing as said voltage amplitude increases and decreasing as said current amplitude increases, said phase tune signal being substantially equal to zero when said input voltage and input current waveforms are in phase, said phase tune signal increasing as said input voltage waveform leads said input current waveform and decreasing as said input voltage waveform lags said input current waveform, said detection means further comprising means for generating a normalizing signal as a function of a selected one of said voltage waveform amplitude at said input port and said current waveform amplitude at said input port;
• and
• control means responsive to said amplitude and phase tune signals for adjusting the values of said first and second variable reactive components to provide a tuned condition at said input port, said control means including a first adjustment means for modifying the value of said first variable reactive component as a function of said amplitude tune signal, a second adjustment means for modifying the value of said second variable reactive component as a function of said phase tune signal, said control means further comprising amplitude normalization means for normalizing said amplitude tune signal with respect to said normalizing signal.

An automatic impedance matching apparatus ..having an input port coupled to a signal generator and an output port coupled to a load, said input and output ports each having a signal line and a ground line, said signal generator having a predetermined characteristic impedance, said apparatus comprising:

• matching means coupled between said input port and output port for matching the impedance of said load to the impedance of said signal generator, said matching means including a first variable reactive component and a second variable reactive component;
• a detection means for generating an amplitude tune signal related to the difference of the voltage waveform amplitude at said input port and the product of said predetermined characteristic impedance and the current waveform amplitude at said input port and for generating a phase tune signal related to the phase difference between the voltage and current waveforms at said input port, said amplitude tune signal increasing as said voltage amplitude increases and decreasing as said current amplitude increases, said phase tune signal being substantially equal tn zero when said input voltage and input current waveforms are in phase, said phase tune signal increasing as said input voltage waveform leads said input current waveform and decreasing as said input voltage waveform lags said input current waveform, said detection means further comprising means for generating a normalizing signal as a function of a selected one of said voltage waveform amplitude at said input port and said current waveform amplitude at said input port;
• and
• control means responsive to said amplitude and phase tune signals for adjusting the values of said first and second variable reactive components to provide a tuned condition at said input port, said control means including a first adjustment means for modifying the value of said first variable reactive component as a function of said amplitude tune signal, a second adjustment means for modifying the value of said second variable reactive component as a function of said phase tune signal, said control means further comprising phase normalization means for normalizing said phase tune signal with respect to said normalizing signal.