Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
297 words
Apparatus useful for mapping acoustic pressure fields in the range of 10 Hz to 2 MHz, comprising: a distributed electrostatic transducer, functioning as a strip transmission line, which includes: a flat, substantially rectangular, metal plate, one surface of which is rough, the plate having a length generally in the range of 10 to 100 wavelengths of the acoustic frequency at which the mapping is to be done, and a width and thickness in the range of 0.01 lambda to 0.05 lambda ; a rectangular strip of dielectric foil disposed under surface tension on the rough surface of substantially the entire metal plate so that the foil touches only the most protruding parts of the surface; and a long, narrow, rectangular, metallic strip disposed on and attached to the dielectric foil, the strip being exposed to, and therefore defining, an acoustic pressure field; and a duplexer, electrically connected to the metallic strip and to the flat plate, connectable to a source of electrical input signals, and having output terminals at which an output electrical signal may be measured; with the result that, when an electromagnetic delta function delta (to) is applied at the input to the duplexer, electromagnetic waves travel in both directions along the strip transmission line, the duplexer having the function of separating the signal reaching the output terminals of the duplexer from the applied signal (E(t-to)) delta (to) which is interrogating the line, the returning signal containing two groups of frequencies: 1. low frequency components wn identical to those present in the acoustic pressure field, and 2. high-frequency components containing wave vectors kn, also present in the acoustic pressure field, the two components being readily separable, because of the great differences in their frequencies, and hence any specific pressure field P(k, w) may be reconstructed.
Claim 2
Dependent Claim
297 words
Apparatus useful for mapping acoustic pressure fields in the range of 10 Hz to 2 MHz, comprising: a distributed electrostatic transducer, functioning as a strip transmission line, which includes: a flat, substantially rectangular, metal plate, one surface of which is rough, the plate having a length generally in the range of 10 to 100 wavelengths of the acoustic frequency at which the mapping is to be done, and a width and thickness in the range of 0.01 lambda to 0.05 lambda ; a rectangular strip of dielectric foil disposed under surface tension on the rough surface of substantially the entire metal plate so that the foil touches only the most protruding parts of the surface; and a long, narrow, rectangular, metallic strip disposed on and attached to the dielectric foil, the strip being exposed to, and therefore defining, an acoustic pressure field; and a duplexer, electrically connected to the metallic strip and to the flat plate, connectable to a source of electrical input signals, and having output terminals at which an output electrical signal may be measured; with the result that, when an electromagnetic delta function delta (to) is applied at the input to the duplexer, electromagnetic waves travel in both directions along the strip transmission line, the duplexer having the function of separating the signal reaching the output terminals of the duplexer from the applied signal (E(t-to)) delta (to) which is interrogating the line, the returning signal containing two groups of frequencies: 1. low frequency components wn identical to those present in the acoustic pressure field, and 2. high-frequency components containing wave vectors kn, also present in the acoustic pressure field, the two components being readily separable, because of the great differences in their frequencies, and hence any specific pressure field P(k, w) may be reconstructed.
Claim 3
Dependent Claim
38 words
high-frequency components containing wave vectors kn, also present in the acoustic pressure field, the two components being readily separable, because of the great differences in their frequencies, and hence any specific pressure field P(k, w) may be reconstructed.
Claim 4
Dependent Claim
38 words
high-frequency components containing wave vectors kn, also present in the acoustic pressure field, the two components being readily separable, because of the great differences in their frequencies, and hence any specific pressure field P(k, w) may be reconstructed.
Claim 5
Dependent Claim
86 words
The apparatus according to claim 1, wherein the distributed electrostatic transducer includes the following properties: the metal plate is of porous stainless steel; the roughness of the plate is in the range of 10 microns; the dielectric foil is made of polyethylene terephthalate, having a thickness in the range of 1 mil; the metallic strip is of aluminum, of approximately the same length as, but shorter than, the plate, of one-third the width of the plate, and having a thickness in the range of 1 micron.