Let's examine the propagation of radio waves in seawater. This topic is interesting due to underwater...

 

  
 

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Let's examine the propagation of radio waves in seawater. This topic is interesting due to underwater connections, such as in submarines. Due to the electrical conductivity, the permittivity of seawater is a complex number, and so is the wave number k = kr - jki. In the lecture, a plane wave solution propagating in the positive z-axis direction was presented: E(z) u Eg e-kiz e-ikrz, where the direction of the electric field u is the real unit vector in the xy-plane. a. Write an expression for the magnetic field H(z) corresponding to the electric field. Use the symbol n for the complex wave impedance. b. Write an expression for the complex Poynting vector S(z) in the most simplified form:S(z)=E(z) x H (2).. Interpret the expression. c. At the reference distance, the electric field strength of the plane wave is 1.0 mV/m. How far (in meters) does one need to go for the plane wave's strength to have attenuated by 30 dB (two significant figures) from the reference distance strength when the frequency is 1.0 kHz and 10 GHz. The attenuation L in decibels at a distance d from the reference point zo is defined as: IS(zo)! dB L(d) = 10 log10 S(zo+d)| The electrical properties of seawater at radio frequencies are relative (real) permittivity ar = 81 and conductivity = 4.0 S/m. Let's examine the propagation of radio waves in seawater. This topic is interesting due to underwater connections, such as in submarines. Due to the electrical conductivity, the permittivity of seawater is a complex number, and so is the wave number k = kr - jki. In the lecture, a plane wave solution propagating in the positive z-axis direction was presented: E(z) u Eg e-kiz e-ikrz, where the direction of the electric field u is the real unit vector in the xy-plane. a. Write an expression for the magnetic field H(z) corresponding to the electric field. Use the symbol n for the complex wave impedance. b. Write an expression for the complex Poynting vector S(z) in the most simplified form:S(z)=E(z) x H*(z).. Interpret the expression. c. At the reference distance, the electric field strength of the plane wave is 1.0 mV/m. How far (in meters) does one need to go for the plane wave's strength to have attenuated by 30 dB (two significant figures) from the reference distance strength when the frequency is 1.0 kHz and 10 GHz. The attenuation L in decibels at a distance d from the reference point zo is defined as: IS(zo)! dB L(d) = 10 log10 S(zo+d)| The electrical properties of seawater at radio frequencies are relative (real) permittivity ar = 81 and conductivity = 4.0 S/m. Let's examine the propagation of radio waves in seawater. This topic is interesting due to underwater connections, such as in submarines. Due to the electrical conductivity, the permittivity of seawater is a complex number, and so is the wave number k = kr - jki. In the lecture, a plane wave solution propagating in the positive z-axis direction was presented: E(z) u Eg e-kiz e-ikrz, where the direction of the electric field u is the real unit vector in the xy-plane. a. Write an expression for the magnetic field H(z) corresponding to the electric field. Use the symbol n for the complex wave impedance. b. Write an expression for the complex Poynting vector S(z) in the most simplified form:S(z)=E(z) x H (2).. Interpret the expression. c. At the reference distance, the electric field strength of the plane wave is 1.0 mV/m. How far (in meters) does one need to go for the plane wave's strength to have attenuated by 30 dB (two significant figures) from the reference distance strength when the frequency is 1.0 kHz and 10 GHz. The attenuation L in decibels at a distance d from the reference point zo is defined as: IS(zo)! dB L(d) = 10 log10 S(zo+d)| The electrical properties of seawater at radio frequencies are relative (real) permittivity ar = 81 and conductivity = 4.0 S/m. Let's examine the propagation of radio waves in seawater. This topic is interesting due to underwater connections, such as in submarines. Due to the electrical conductivity, the permittivity of seawater is a complex number, and so is the wave number k = kr - jki. In the lecture, a plane wave solution propagating in the positive z-axis direction was presented: E(z) u Eg e-kiz e-ikrz, where the direction of the electric field u is the real unit vector in the xy-plane. a. Write an expression for the magnetic field H(z) corresponding to the electric field. Use the symbol n for the complex wave impedance. b. Write an expression for the complex Poynting vector S(z) in the most simplified form:S(z)=E(z) x H*(z).. Interpret the expression. c. At the reference distance, the electric field strength of the plane wave is 1.0 mV/m. How far (in meters) does one need to go for the plane wave's strength to have attenuated by 30 dB (two significant figures) from the reference distance strength when the frequency is 1.0 kHz and 10 GHz. The attenuation L in decibels at a distance d from the reference point zo is defined as: IS(zo)! dB L(d) = 10 log10 S(zo+d)| The electrical properties of seawater at radio frequencies are relative (real) permittivity ar = 81 and conductivity = 4.0 S/m.