摘要:
An apparatus for matching the variable impedance of a load with the fixed impedance of a radio frequency (RF) power generator to provide maximum power transfer. The impedance matching network further allows an RF power generator to vary the frequency of the voltage applied to a load, e.g., a plasma chamber as may be utilized in semiconductor or flat panel plasma display manufacturing processes. The impedance matching network further utilizes fixed solid state components to adjust the impedance of the attached load to provide maximum power transfer between the generator and the load. A parallel switched capacitor network is controlled by an electrical switching means such as PIN diodes to turn fixed capacitors on or off. A means for varying the frequency of the applied voltage is used to match the impedance of the load with the impedance of the RF power generator within milliseconds.
摘要:
There is provided by this invention an improved rf power control device for plasma applications for optimization of the feedback control voltage in the presence of harmonic and non-harmonic spurious frequencies. In this system, an oscillator and mixer, similar to those normally used in radio receiver applications are placed at the sampled output of the solid state rf signal source used for plasma ignition. The sampled output is mixed to a low frequency and filtered to remove the spurious frequencies that is created in the non-linear plasma. In this way, the feedback power control essentially ignores the spurious frequencies. In this application, the oscillator and mixer do not interfere with other desirable system characteristics and effectively isolate the feedback control voltage from changes in plasma spurious content. This allows rf power to be delivered to the plasma with greater accuracy than would otherwise be possible with conventional power control device and methods.
摘要:
A method and apparatus for measuring electrical characteristics (e.g. current, voltage, phase, etc.) between a power source and a load at a set of harmonic frequencies to determine information about the load (e.g., load impedance, power dissipation, etc). According to one aspect of the invention, a first circuit detects a set of electrical characteristics (e.g., current, voltage, and/or phase) of a signal between the power source and the load. A second circuit, coupled to the first circuit to receive the set of electrical characteristics, provides data representing the set of electrical characteristics at a harmonic frequency associated with the signal. A third circuit, coupled to the second circuit, receives the data and determines information about the load (e.g., impedance, power dissipation, discharge current, etc.) at the harmonic frequency. The information could be used in any number of ways, such as controlling an impedance matching network that may be used in conjunction with the power source and the load, identifying/monitoring a load condition(s), etc.
摘要:
A bathroom scale which uses an electronic circuit for providing a digital output voltage in response to the placing of a weight thereon, the electronic circuit having operational amplifier circuits which use both a positive power supply and a negative power supply, the latter assuring that the op-amps always return to a stabilized ground reference point to assure repeatability of weight measurement. The unit includes means for permitting the digital output voltage to reach a steady state value during a selected time period after a weight is placed on the scale and for preventing such steady state value from changing after such selected time period. The gain of the op-amp circuitry is adjustable to permit scale calibration to be performed.
摘要:
There is provided by this invention an improved rf power control device for plasma applications for optimization of the feedback control voltage in the presence of harmonic and non-harmonic spurious frequencies. In this system, an oscillator and mixer, similar to those normally used in radio receiver applications are placed at the sampled output of the solid state rf signal source used for plasma ignition. The sampled output is mixed to a low frequency and filtered to remove the spurious frequencies that is created in the non-linear plasma. In this way, the feedback power control essentially ignores the spurious frequencies. In this application, the oscillator and mixer do not interfere with other desirable system characteristics and effectively isolate the feedback control voltage from changes in plasma spurious content. This allows rf power to be delivered to the plasma with greater accuracy than would otherwise be possible with conventional power control device and methods.
摘要:
Matching the variable impedance of a load with the fixed impedance of a radio frequency (RF) power generator to provide maximum power transfer. The impedance matching network further allows a RF power generator to vary the frequency of the voltage applied to a load, e.g., a plasma chamber as may be utilized in semiconductor or flat panel plasma display manufacturing processes. The impedance matching network further utilizes fixed solid state components to adjust the impedance of the attached load to provide maximum power transfer between the generator and the load. A parallel switched capacitor network is controlled by an electrical switching means such as PIN diodes to turn fixed capacitors on or off. A means for varying the frequency of the applied voltage is used to match the impedance of the load with the impedance of the RF power generator within milliseconds.