Configurable ultrasonic imager

Abstract

An imaging device includes a two dimensional array of piezoelectric elements. Each piezoelectric element includes: a piezoelectric layer; a bottom electrode disposed on a bottom side of the piezoelectric layer and configured to receive a transmit signal during a transmit mode and develop an electrical charge during a receive mode; and a first top electrode disposed on a top side of the piezoelectric layer; and a first conductor, wherein the first top electrodes of a portion of the piezoelectric elements in a first column of the two dimensional array are electrically coupled to the first conductor.

What is claimed is: 
     
         1 . A circuit for controlling a plurality of piezoelectric elements, comprising:
 a first conductor for transmitting a driving signal to one or more of the plurality of piezoelectric elements therethrough; and   a second conductor for transmitting a sensor signal from one or more of the plurality of piezoelectric elements therethrough; and   a plurality of circuit elements that each comprise:
 a first switch having a first end electrically coupled to the second conductor and a first electrode of a piezoelectric element; 
 a second switch having first and second ends, the first end of the second switch being electrically coupled to the first conductor; 
 a transmit driver electrically coupled to the second end of the second switch and configured to transmit a signal to a first electrode of a piezoelectric element upon receiving the driving signal through the second end of the second switch; and 
 a third switch having first and second ends, the first end of the third switch being electrically coupled to the second end of the second switch, the second end of the third switch being electrically coupled to an electrode of a piezoelectric element. 
   
     
     
         2 . The circuit of  claim 1 , wherein the second conductor is electrically coupled to a DC bias voltage during operation of the plurality of piezoelectric elements. 
     
     
         3 . The circuit of  claim 1 , further comprising a third conductor, wherein each circuit element of the plurality of circuit elements further comprises a fourth switch having first and second ends, the first end of the fourth switch being electrically coupled to the third conductor, the second end of the fourth switch being electrically coupled to a third electrode of a piezoelectric element. 
     
     
         4 . The circuit of  claim 3 , wherein the third conductor is electrically coupled to a DC bias voltage during operation of the plurality of piezoelectric elements. 
     
     
         5 . The circuit of  claim 1 , further comprising an electrical circuit electrically coupled to the second conductor and configured to process a signal received through the second conductor. 
     
     
         6 . An electrical system for controlling piezoelectric elements, comprising:
 a first electrical circuit electrically coupled to a first conductor and configured to process a signal received through the first conductor;   an array of piezoelectric elements that each have a piezoelectric layer, a bottom electrode disposed on a bottom side of the piezoelectric layer, and first and second top electrodes disposed on a top side of the piezoelectric layer, the first top electrodes of a portion of piezoelectric elements in a first column of the array being electrically coupled to the first conductor;   a second conductor being electrically coupled to the second top electrodes of a portion of piezoelectric elements in a second column of the array;   a second electrical circuit for processing a signal;   a transmit driver for sending a signal to the second conductor; and
 a switch having first and second ends, the first end being electrically coupled to the second conductor, and the second end being selectively coupled to one of the second electrical circuit and the transmit driver. 
   
     
     
         7 . The electrical system of  claim 6 , wherein the first and second electrical circuits may be formed in an ASIC chip. 
     
     
         8 . The electrical system of  claim 6 , wherein n electrical circuits may be formed in an ASIC chip. 
     
     
         9 . The electrical system of  claim 7 , wherein the array of piezoelectric elements may be connected to the first and second electrical circuits within 25 μm-100 μm. 
     
     
         10 . The electrical system of  claim 8 , wherein the array of piezoelectric elements may be connected to the n electrical circuits within 25 μm-100 μm. 
     
     
         11 . The electrical system of  claim 10 , further comprising one control unit for controlling the n circuits. 
     
     
         12 . The electrical system of  claim 6 , wherein the array is a two-dimensional array. 
     
     
         13 . The electrical system of  claim 6 , wherein the first electrode may be connected to a ground or a DC bias via the first conductor. 
     
     
         14 . The electrical system of  claim 6 , wherein the second electrode may be connected to an electrical circuit through a signal conductor. 
     
     
         15 . The electrical system of  claim 6 , wherein each electrical circuit comprises a transmit driver, a receiver amplifier, a switch having one terminal electrically coupled to the conductor and another terminal that toggles between the first and second conductors coupled to the transmit driver and amplifier. 
     
     
         16 . The electrical system of  claim 15 , wherein during a transmit mode, the switch may connect the transmit driver to the piezoelectric element so that a signal is transmitted to the top electrode of the piezoelectric element. 
     
     
         17 . The electrical system of  claim 15 , wherein during a receive mode, the switch may connect the amplifier to the piezoelectric element so that a signal is transmitted from the top electrode of the piezoelectric element to the amplifier.