Wide-band matching network for piezoelectric transducer

Claim 2

A wide band network comprising means for matching the impedance of a signal-conducting line having a characteristic impedance of about 50 ohms to an electrode, a piezoelectric transmitter having said electrode as a part thereof, said transmitter having an equivalent ohmic resistance R.sub.Ω series with an equivalent capacitance C o , the resistance R.sub.Ω being approximately one-tenth of the reactance of said capacitance C o , and a reactance X o not greater than about 50 ohms at a center frequency f o of the frequency band of signals to be transmitted and said matching means comprising: a series combination of a first capacitor having capacitance C 1 and a second inductor having an inductance L 2 connecting said signal-conducting line to said electrode; and a first inductor having an inductance L 1 connecting said electrode to ground; wherein the values C 1 , L 1 , and L 2 are determined approximately by the following relationships: ##EQU5##

Claim 3

A wide band network as claimed in claim 1, wherein, for f o greater than about 1 GHz, said first and second inductors respectively comprise wires attached to said electrode, and said first capacitor comprises a chip capacitor.

Claim 4

A wide band network for matching the impedance of a signal-conducting line having a characteristic impedance of about 50 ohms to an electrode of a piezoelectric transmitter, said transmitter having an equivalent ohmic resistance R.sub.Ω in series with an equivalent capacitance C o , the resistance R.sub.Ω being approximately one-tenth of the reactance of said capacitance C o , and a reactance X o between about 50 to 250 ohms at a center frequency f o of the frequency band of signals to be transmitted, comprising: a first inductor having an inductance L 3 connecting said signal-conducting line to said electrode; a first capacitor having a capacitance C 2 connecting said signal-conducting line to ground; and a second inductor having an inductance L 4 connected in parallel with said first capacitor and also connecting said signal-conducting line to ground; wherein the values C 2 , L 3 , and L 4 are determined approximately by the following relationships: ##EQU6##

Claim 5

A wide band network for matching the impedance of a signal-conducting line having a characteristic impedance of about 50 ohms to an electrode of a piezoelectric transmitter, said transmitter having an equivalent ohmic resistance R.sub.Ω in series with an equivalent capacitance C o , the resistance R.sub.Ω being approximately one-tenth of the reactance of said capacitance C o , and a reactance X o between about 50 to 250 ohms at a center frequency f o of the frequency band of signals to be transmitted, comprising: a first inductor having an inductance L 3 connecting said signal-conducting line to said electrode; a first capacitor having a capacitance C 2 connecting said signal-conducting line to ground; and a second inductor having an inductance L 4 connected in parallel with said first capacitor and also connecting said signal-conducting line to ground; wherein the values C 2 , L 3 , and L 4 are determined approximately by the following relationships: ##EQU6##

Claim 6

A wide band network as claimed in claim 3 wherein, for f o greater than about 1 GHz, said first inductor comprises a wire.

Claim 7

A wide band network comprising means for matching the impedance of a signal-conducting line having a characteristic impedance of about 50 ohms to an electrode, a piezoelectric transmitter having said electrode as a part thereof, said transmitter having an equivalent ohmic resistance R.sub.Ω in series with an equivalent capacitance C o , the resistance R.sub.Ω being approximately one-tenth of the reactance of said capacitance C o , and a reactance X o not less than about 250 ohms at a center frequency f o of the frequency band of signals transmitted, and said matching means comprising a series combination of a λ/4 length impedance line having a characteristic impedance Z and an inductor having an inductance L 5 for connecting said signal-conducting line to said electrode, where λ is the signal wavelength at center frequency f o ; wherein the values Z and L 5 are determined approximately by the following relationships: ##EQU7##

Claim 8

A wide band network comprising means for matching the impedance of a signal-conducting line having a characteristic impedance of about 50 ohms to an electrode, a piezoelectric transmitter having said electrode as a part thereof, said transmitter having an equivalent ohmic resistance R.sub.Ω in series with an equivalent capacitance C o , the resistance R.sub.Ω being approximately one-tenth of the reactance of said capacitance C o , and a reactance X o not less than about 250 ohms at a center frequency f o of the frequency band of signals transmitted, and said matching means comprising a series combination of a λ/4 length impedance line having a characteristic impedance Z and an inductor having an inductance L 5 for connecting said signal-conducting line to said electrode, where λ is the signal wavelength at center frequency f o ; wherein the values Z and L 5 are determined approximately by the following relationships: ##EQU7##