1. A circuit for power amplification, the circuit comprising:
a. a power amplifier, the power amplifier having an input port and an output port, the power amplifier having at least one transistor, and a current mirror is coupled between a base terminal of the at least one transistor and a ground node; and
b. a protection circuit connected as a negative feedback loop around the power amplifier, the protection circuit including:
i. a detector circuit configured to detect an output voltage from the output port, wherein the detector circuit provides a driver signal when the output voltage exceeds a predefined threshold;
ii. a driver circuit configured to receive the driver signal from the detector circuit, wherein the driver circuit is configured to adjust a gain and phase margin of the negative feedback loop to maintain stability, and wherein the driver circuit includes a filter circuit that provides a filtered signal; and
iii. an attenuator circuit coupled with the input port and the driver circuit, wherein the attenuator circuit is configured to receive the filtered signal from the filter circuit and attenuate an input voltage at the input port, wherein attenuation in the input voltage results in reduction of the output voltage below the predefined threshold.
2. The circuit of claim 1 further comprising a resistor coupled to the current mirror, wherein the resistor and the current mirror are configured to provide temperature compensation for the power amplifier.
3. The circuit of claim 1, wherein the input port is coupled to an input matching circuit, wherein the input matching circuit comprises a high pass filter circuit.
4. The circuit of claim 1, wherein the output port is coupled to an output matching circuit, wherein the output matching circuit provides impedance transformation.
5. The circuit of claim 1, wherein the detector circuit comprises one or more stacks of diodes, and wherein the number of diodes in each of the one or more stacks and the number of stacks determine the predefined threshold.
6. The circuit of claim 1, wherein the driver circuit further comprises an amplifier coupled to the filter circuit and the detector circuit, the amplifier being configured to conduct current based on the driver signal received from the detector circuit.
7. The circuit of claim 1, wherein the attenuator circuit is a tee attenuator circuit.
8. A method of protecting a power amplifier from damage due to voltage breakdown, the method comprising the steps of:
a. detecting an output voltage at an output port of the power amplifier; and
b. providing a negative feedback signal at an input port of the power amplifier for reducing the output voltage of the power amplifier below a predefined threshold, the step of providing the negative feedback signal comprising:
i. providing a driver signal when the output voltage exceeds the predefined threshold, the driver signal being provided by a detector circuit, the detector circuit having one or more stacks of diodes, the number of diodes in each of the one or more stacks and the number of stacks determining the predefined threshold;
ii. providing a filtered signal based on the driver signal; and
iii. attenuating an input voltage at the input port based on the filtered signal.
9. The method of claim 8, wherein the filtered signal is provided by a filter circuit, the filter circuit being coupled to a transistor, and wherein the transistor conducts when the driver signal is received from the detector circuit.
10. The method of claim 8, wherein the attenuation is performed by a tee attenuator.
11. A protection circuit for a power amplifier, the power amplifier having an input port and an output port, the protection circuit comprising:
a. a detector circuit configured to detect an output voltage from the output port, the detector circuit providing a driver signal when the output voltage exceeds a predefined threshold;
b. a driver circuit configured to receive the driver signal from the detector circuit, the driver circuit including a filter circuit that provides a filtered signal; and
c. an attenuator circuit coupled with the input port and the driver circuit, the attenuator circuit being configured to receive the filtered signal from the filter circuit and attenuate an input voltage to the input port, and wherein a reduction in the input voltage results in a reduction of the output voltage below the predefined threshold, and
wherein the power amplifier comprises at least one transistor and a current mirror is coupled between a base terminal of the at least one transistor and a ground node.
12. The protection circuit of claim 11 further comprising a resistor coupled to the current mirror, the resistor and the current mirror being configured to provide temperature compensation for the power amplifier.
13. The protection circuit of claim 11, wherein the detector circuit comprises one or more stacks of diodes, wherein the number of diodes in each of the one or more stacks and the number of stacks determine the predefined threshold.
14. The protection circuit of claim 11, wherein the driver circuit further comprises an amplifier coupled to the filter circuit and the detector circuit, the amplifier being configured to conduct current based on the driver signal received from the detector circuit.
15. The protection circuit of claim 11, wherein the attenuator circuit is a tee attenuator circuit.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-10. (canceled)
11. An ultrasound system comprising:
a probe operable to transmit ultrasound signals to a target object containing a periodically moving object and to receive ultrasound echo signals reflected from the target object;
a processor operable to generate volume data based on the ultrasound echo signals;
a display unit to display a 3-dimensional ultrasound image constructed based on the volume data; and
a user input unit to receive user inputs regarding reference image setup information and M-mode line setup information associated with the 3-dimensional ultrasound image,
wherein the processor is configured to generate a reference image representing a plane cut through the 3-dimensional ultrasound image using the volume data, the cut plane designated based on the reference image setup information and to generate a M-mode line on the reference image which is designated based on the M-mode line setup information, and
M-mode images are generated and displayed based on the M-mode line on the reference image which is designated using the 3-dimensional ultrasound image.
12. The ultrasound system of claim 11, wherein the user input unit is further configured to receive rotation information upon the 3-dimensional ultrasound image, and
the processor is configured to control a rotation of the 3-dimensional ultrasound image displayed on the display unit based on the rotation information so that the reference image and the M-mode line can be designated by a user using the 3-dimensional image rotated to any one of a plurality of viewing angles.
13. The ultrasound system of claim 12, wherein the processor is configured to determine a moving period of the moving object and interpolate the volume data to contain a same number of frames in each moving period.
14. A method comprising:
using a probe to transmit ultrasound signals to a target object containing a periodically moving object and receiving ultrasound echo signals reflected from the target object;
generating volume data based on the ultrasound echo signals;
displaying a 3-dimensional ultrasound image constructed based on the volume data;
receiving user inputs regarding reference image setup information and M-mode line setup information associated with the 3-dimensional ultrasound image;
generating a reference image representing a plane cut through the 3-dimensional ultrasound image using the volume data, the cut plane being designated based on the reference image setup information;
generating a M-mode line on the reference image which is designated based on the M-mode line setup information; and
displaying M-mode images based on the M-mode line on the reference image which is designated using the 3-dimensional ultrasound image.
15. The method of claim 14, further comprising:
receiving a user input regarding rotation information upon the displayed 3-dimensional ultrasound image; and
rotating the displayed 3-dimensional ultrasound image based on the rotation information so that the reference image and the M-mode line can be designated by a user using the 3-dimensional image rotated to any one of a plurality of viewing angles.
16. The method of claim 15, further comprising:
determining a moving period of the moving object; and
interpolating the volume data to contain a same number of frames in each moving period.
17. An ultrasound system comprising:
a probe operable to transmit ultrasound signals to a target object containing a periodically moving object and to receive ultrasound echo signals reflected from the target object;
a processor operable to generate volume data based on the ultrasound echo signals and a period of the moving object;
a display unit to display a 3-dimensional ultrasound image constructed based on the volume data; and
a user input unit to receive a user input as to M-mode line setup information associated with the 3-dimensional ultrasound image,
wherein the processor is configured to generate a reference image representing a plane cut through the 3-dimensional ultrasound image using the volume data, and to generate a M-mode line on the reference image based on the M-mode line setup information, and
M-mode images corresponding to the M-Mode line on the reference image are generated and displayed.
18. A method comprising:
transmitting ultrasound signals, by a probe, to a target object containing a periodically moving object and receiving ultrasound echo signals reflected from the target object;
generating volume data based on the ultrasound echo signals and a period of the moving object;
displaying a 3-dimensional ultrasound image constructed based on the volume data;
receiving a user input as to M-mode line setup information associated with the 3-dimensional ultrasound image;
generating a reference image representing a plane cut through the 3-dimensional ultrasound image using the volume data;
generating a M-mode line on the reference image based on the M-mode line setup information; and
displaying M-mode images corresponding to the M-Mode line on the reference image.