KR20170059672A

KR20170059672A - The broadband analog receiver for high frequency image ultrasonic waves system

Info

Publication number: KR20170059672A
Application number: KR1020150163897A
Authority: KR
Inventors: 최호종
Original assignee: 금오공과대학교 산학협력단
Priority date: 2015-11-23
Filing date: 2015-11-23
Publication date: 2017-05-31

Abstract

The present invention relates to a broadband analog receiver for a high frequency image ultrasonic wave system, and more particularly, to a broadband analog receiver for a high frequency image ultrasonic wave system which can minimize attenuation and distortion of an ultrasonic signal by using a serial two-stage and parallel four-stage transistor in a limiter circuit, and reduces a low-frequency signal and amplifies a high-frequency signal by forming an input capacitor to in amplifier so as to improve the performance of a high-frequency amplifier.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a broadband analog receiver for a high-frequency imaging ultrasound system,

The present invention relates to a wideband analogue receiver for a high frequency image ultrasound system, and more particularly, to a method and apparatus for minimizing attenuation and distortion of an ultrasonic signal by using a transistor of two stages in series and a stage of four stages in a limiter circuit, To a wideband analogue receiver for a high frequency imaging ultrasound system which reduces the low frequency signal and amplifies the high frequency signal to improve the performance of the high frequency amplifier.

Medical Ultrasound Imaging Systems is a system that uses ultrasonic transducer (ultrasonic transducer) to transmit the audible frequency (20kHz or higher) ultrasonic signal to the inside of human body and animal and displays the structural image through diffusion, reflection, absorption and scattering. It is an imaging diagnostic medical device that provides.

Ultrasonic transducers are divided into single transducer with one part and array transducer with several parts.

On the other hand, the quality of the ultrasound image is largely influenced by the ultrasonic probe, and the role of the power amplifier among the electronic components included in the ultrasound system plays the most important role in operating the ultrasonic image.

Therefore, the design of a good power amplifier has a significant impact on the performance of the entire high-frequency imaging ultrasound system.

As shown in FIG. 1, the HV MUX / DEMUX (high voltage multiplexer / demultiplexer) is used to reduce the channel of the transceiver.

The high voltage from the HV TxAMPs (high voltage transmitter amplifier) passes through the CABLE (cable) through the HV MUX / DEMUX to the TRANSDUCER.

The biosignals from TRANSDUCER are amplified by the LNA (Low Noise Amplifier) through the HVMUX / DE-MUX and T / R SWITCHES (Transmit / Receive Switch), and through the RX BEAMFORER, IMAGING and MOTION PROCESSING, SPECTRAL DOPPLER PROCESSING, COLOR DOPPLER ) AUDIO OUTPUT (audio) or DISPLAY (video) through different signal processing stages such as PROCESSING.

2 shows a biological ultrasound microscope system for a single transducer ultrasonic wave. A high voltage signal from a transmitter is transmitted to an ultrasonic transducer (LiNbO3 Transducer) through an expander (bi-directional diode) and a coaxial cable (coaxial cable) The ultrasonic waves are applied to the sample in the water tank.

At the same time, a high-voltage signal is applied at the same time, so a protection circuit such as a limiter is necessary since it must protect the receiver at the same time.

However, this limiter actually affects the quality of the signal in high frequency signals.

The reflected ultrasound is converted into an electric signal through a single transducer, amplified by a receiver, converted into a digital signal through an analog to digital converter (ADC), modulated by the FPGA, Waveforms are shown.

However, the above configuration can not reduce the signal loss of the limiter (protection circuit), and thus can not improve the value of the signal-to-noise-ratio (SNR) of the entire receiver.

That is, the limiter should minimize the loss of the small signal echo (ultrasonic reflected signal) and prevent the high voltage signal from reaching the preamplifier.

Korean Utility Model Publication No. 2000-0009734 (Jun. 2000)

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to minimize the attenuation and distortion of ultrasonic signals by using transistors of two stages in series and four stages in parallel in a limiter circuit have.

Another object of the present invention is to reduce the low-frequency signal and amplify the high-frequency signal by configuring the input capacitor in the amplifier to improve the performance of the high-frequency amplifier.

According to an aspect of the present invention, there is provided a wideband analogue receiver for a high frequency imaging ultrasound system,

A transistor type limiter 100 configured by arranging transistors in two stages in parallel and four stages in parallel;

And an amplifier 200 including input capacitors 210 and C1 for reducing a low frequency signal and amplifying a high frequency signal.

According to another aspect of the present invention, there is provided a wideband analog receiver for a high-frequency image ultrasound system,

In the limiter circuit, attenuation and distortion of the ultrasonic signal can be minimized by using two-stage and two-stage four-stage transistors.

In addition, an input capacitor is formed in the amplifier to reduce the low frequency signal and amplify the high frequency signal, thereby improving the performance of the high frequency amplifier.

That is, by using a new high frequency ultrasonic analog receiver structure, it is possible to increase the resolution by using a less loss and a wide frequency band and to improve the sensitivity of the receiver, thereby improving the sensitivity of the signal to noise of the entire ultrasonic system have.

1 is a conceptual diagram showing an ultrasound system.
2 is a conceptual diagram showing a bio-ultrasonic microscope system for a single transducer ultrasonic wave.
3 is a block diagram of a limiter using a transistor of a wideband analog receiver for a high-frequency image ultrasound system according to an embodiment of the present invention.
FIG. 4A is an equivalent circuit of a power transistor, and FIG. 4B is a circuit diagram showing one equivalent circuit of the transistor of FIG. 3 as an equivalent circuit to which a drain and a gate of a power transistor are connected.
FIG. 5A is a circuit diagram illustrating a capacitive input-based preamplifier, and FIG. 5B is a graph of a general pre-processing amplifier (black) and a capacitor input pre-processing amplifier (blue).
6 is a block diagram of an ultrasonic biomicroscope analog system for single ultrasound.
FIG. 7A is a graph showing the maximum voltage magnitude of an ultrasonic echo when a commercial part is used, FIG. 7B is a graph showing a maximum voltage magnitude of an ultrasonic echo when using the receiver of the present invention, and FIG. FIG. 7D is a graph showing the bandwidth of the ultrasonic echo when using the receiver of the present invention. FIG.

The following merely illustrates the principles of the invention. Therefore, those skilled in the art will be able to devise various apparatuses which, although not explicitly described or illustrated herein, embody the principles of the invention and are included in the concept and scope of the invention.

Furthermore, all of the conditional terms and embodiments listed herein are, in principle, only intended for the purpose of enabling understanding of the concepts of the present invention, and are not to be construed as limited to such specifically recited embodiments and conditions do.

It is also to be understood that the detailed description, as well as the principles, aspects and embodiments of the invention, as well as specific embodiments thereof, are intended to cover structural and functional equivalents thereof.

It is also to be understood that such equivalents include all elements contemplated to perform the same function irrespective of currently known equivalents as well as equivalents to be developed in the future.

Hereinafter, embodiments of a wideband analog receiver for a high frequency image ultrasound system according to the present invention will be described in detail.

A transistor type limiter (100) of a wideband analog receiver for a high frequency image ultrasound system,

And the transistors are arranged in two stages in parallel and four stages in parallel.

Meanwhile, a broadband analog receiver for a high-frequency image ultrasound system, including an amplifier for amplifying an ultrasonic signal,

An input capacitor 210 and C1 are formed in the amplifier 200 to reduce a low-frequency signal and amplify a high-frequency signal.

Meanwhile, a wideband analog receiver for a high frequency image ultrasound system,

And an amplifier 200 including input capacitors 210 and C1 for reducing a low-frequency signal and amplifying a high-frequency signal.

And a high voltage diode (110) formed on one side of the transistor type limiter.

And a high voltage diode (110) formed on one side of the transistor type limiter,

The transistor comprising:

BSS 123, and the high voltage diode is implemented by 1N4148.

And a limiter and a preamplifier.

On the other hand, by using CONDUTIVE METAL LAYERS on both sides of the transistor, stress of a fast high voltage signal is reduced.

At this time, the transistor type limiter (100)

The transistors are arranged in two tiers and four tiers in parallel, thereby reducing losses and being able to withstand high voltages.

At this time, the amplifier (200)

And a feedback circuit having resistors Rf and Rs is constituted.

At this time,

The present invention is characterized in that the SNR of the analog receiver is improved by arranging transistors arranged in two stages in parallel and four stages in parallel.

At this time,

The gain is reduced, and the bandwidth is increased.

At this time, by connecting the gate and the drain of the transistor of the transistor-type limiter 100, the loss of the limiter is minimized.

At this time, the attenuation and the distortion of the ultrasonic signal are minimized through the transistors of the series 2 and parallel 4 stages.

3 is a block diagram of a limiter using a transistor of a wideband analog receiver for a high frequency image ultrasound system according to an embodiment of the present invention.

As shown in Fig. 3, the transistor-type limiter 100 of the present invention includes:

That is, two series and four parallel transistors are configured to reduce losses and to withstand higher voltages.

Specifically, the circuit of FIG. 3 comprises a N-channel logic level enhancement-mode field effect transistors (BSS 123) and a high voltage diode 1N4148.

It is usually used for these electronic components because it has to withstand high frequency high voltage signals (about 100V).

Also, relatively large conductive metal layers (0.05 cm wide) are used on both sides of the transistor to reduce the stress of the fast high voltage signal.

In addition, the receiver of the present invention is composed of a limiter (protection circuit) and a preamplifier (usually a passive electronic device) in a high frequency biomicroscope system.

Because this limiter circuit is the first electronic component of the entire receiver circuit, it affects the overall noise figure of the entire receiver (= analog receiver + ADC + FPGA).

Therefore, by configuring the limiter as described above, the signal-to-noise-ratio (SNR) of the entire receiver can be reduced by reducing the signal loss of the limiter (protection circuit) Can be improved.

Normally the limiter should minimize the loss of the small signal echo (ultrasonic reflected signal) and prevent the high voltage signal from reaching the preamplifier.

The preamplifier must have a bandwidth that is large enough to cover the broadband signal from the transducer.

This is because it is necessary to have a wide bandwidth to increase the image resolution of the ultrasound signal.

Therefore, the preamplifier of the present invention usually uses the resistance feedback circuit to reduce the gain of the preamplifier and increase the bandwidth.

4A is an equivalent circuit of a power transistor, and FIG. 4B is a circuit diagram showing one equivalent circuit of the transistor of FIG. 3 as an equivalent circuit to which a drain and a gate of a power transistor are connected.

4A is a basic structure of a power transistor. Since the limiter of the present invention connects the gate and drain of the transistor, the structure of an equivalent circuit is changed as shown in FIG. 4B.

Therefore, in order to minimize the loss of the limiter, a power transistor with a small parasitic resistance (Rds) and a parasitic capacitance (parasitic capacitor, Cgd and Cds) should be selected.

Therefore, in the present invention, a transistor called 'BSS123' was selected.

Of course, because the diode also affects the loss and bandwidth, it also chooses the high voltage diode '1N4148' with small parasitic resistance and parasitic capacitor value.

FIG. 5A is a circuit diagram illustrating a capacitive input-based preamplifier, and FIG. 5B is a graph of a general pre-processing amplifier (black) and a capacitor input pre-processing amplifier (blue).

Typically, high-voltage ultrasonic instruments usually have low sensitivity, so they prefer a preprocessing amplifier with wide bandwidth and high gain.

Therefore, as shown in FIG. 5A, the present invention constitutes a capacitive input-based preamplifier having a feedback circuit having resistors Rf and Rs and an input capacitor Ci.

By constructing such a circuit, it becomes possible to design a preprocessing amplifier having a relatively larger bandwidth at a high voltage in practice, as shown in FIG. 5B.

By using such a protection circuit and a preamplifier, it is possible to provide a high-frequency medical ultrasound device with low signal loss and high resolution.

Meanwhile, in the bio-ultrasonic microscope system as shown in FIG. 6, the receiver of the present invention is compared with a commercial receiver.

7A and 7C, the size and bandwidth of the ultrasonic signal were obtained using a commercial protection circuit (Limiter-Matec DL-1) and a preprocessing amplifier (Panametrics 5900PR, Olympus) And the signal size and bandwidth were obtained using the receiver of FIG.

As shown in the figure, the receiver of the present invention was able to obtain a signal stronger than the general commercial receiver by about 6.8 times, and the bandwidth was similar.

In summary, a broadband analog receiver for a high-frequency image ultrasound system constitutes a limiter using a serial-parallel transistor and a diode.

In addition, a high-frequency amplifier whose performance is improved by using an input capacitor is constructed.

Through the above-described configuration and operation, the effect of minimizing the attenuation and distortion of the ultrasonic signal can be achieved by using the transistors in the two-stage and four-stage in series in the limiter circuit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

100: Transistor type limiter
110: High-voltage diodes
200: amplifier
210: input capacitor

Claims

1. A wideband analog receiver for a high frequency imaging ultrasound system comprising a transistor type limiter,
The transistor-type limiter (100)
Wherein the transistors are arranged in two stages in parallel and four stages in parallel.

1. A wideband analog receiver for a high frequency imaging ultrasound system comprising an amplifier for amplifying an ultrasound signal,
Wherein the input capacitor (210, C1) is configured in the amplifier (200) to reduce the low frequency signal and amplify the high frequency signal.

A wideband analog receiver for a high frequency imaging ultrasound system,
A transistor type limiter 100 configured by arranging transistors in two stages in parallel and four stages in parallel;
And an amplifier 200 including input capacitors 210 and C1 for reducing a low frequency signal and amplifying a high frequency signal.

A wideband analog receiver for a high frequency imaging ultrasound system,
A transistor type limiter 100 configured by arranging transistors in two stages in parallel and four stages in parallel;
And a high voltage diode (110) formed on one side of the transistor type limiter.

A wideband analog receiver for a high frequency imaging ultrasound system,
A transistor type limiter 100 configured by arranging transistors in two stages in parallel and four stages in parallel;
And a high voltage diode (110) formed on one side of the transistor type limiter,
The transistor comprising:
Wherein the high voltage diode is implemented by 1N4148. &Lt; RTI ID = 0.0 > 1, < / RTI >

A wideband analog receiver for a high frequency imaging ultrasound system,
The analog receiver includes:
And a limiter and a preamplifier. &Lt; Desc / Clms Page number 20 >

The method according to any one of claims 1, 3, 4, and 5,
Wherein the transistors are fabricated using CONDUTIVE METAL LAYERS on both sides of the transistor, thereby reducing the stress of the fast high voltage signal.

The method according to any one of claims 1, 3, 4, and 5,
The transistor-type limiter (100)
Wherein the transistors are arranged in two tiers and four tiers in parallel to reduce losses and withstand high voltages. 2. A wideband analogue receiver for a high-frequency imaging ultrasound system, comprising:

The method of claim 3,
The amplifier (200)
And a feedback circuit having resistances (Rf, Rs) is constituted. The wideband analogue receiver for a high-frequency imaging ultrasound system.

The method according to claim 6,
The limiter includes:
Wherein the transistors are arranged in two tiers and four tiers in parallel to improve the SNR of the analog receiver.

10. The method of claim 9,
Wherein the feedback circuit comprises:
Wherein the gain is reduced and the bandwidth is increased. &Lt; RTI ID = 0.0 > A < / RTI > wideband analog receiver for a high frequency imaging ultrasound system.

The method of claim 3,
And limits the loss of the limiter by coupling the gate and drain of the transistor of the transistor-type limiter (100).

The method according to any one of claims 1, 3, and 4,
And the attenuation and the distortion of the ultrasonic signal are minimized through the transistors of the series 2 and parallel 4 stages.