Is sinusoidal wave signal is a type of continuous wave that has a smooth and repetitive oscillation. It is based on the sine or cosine trigonometric function, which describes the curve of the wave. Sinusoidal wave signals are common in mathematics, physics, engineering, signal processing, and many other fields. In this article, we will explain what a sinusoidal wave signal is, how it is characterized, and why it is important.
Roimh an sínadh de shíniúil wave signal, lig sinn éirí leis go díreach céard atá i gceist le síniúil. Is ionadaíocht ar aon mhaireachtáil atá ag athrú trí ama nó spás. Mar shampla, fuaim ghutha, teocht seomra, voltage bataery, agus suíomh carr suntar siunáil. Siúnáil is féidir leis a mhéadú agus a chur i bhfeidhm mar luachanna ag pointí éagsúla am nó spás.
Is féidir siúnáil a léiriú mar fheidhm de thimp isteach nó spás, ag léiriú conas a athraíonn an luach tríd an réimse. Seo an léiriú grafach den siúnáil. Mar shampla, an graif thíos léiríonn siúnáil a ionraíonn teocht seomra thar lá amháin.
Dáil siúnáil tábhachtach is constant, ciallmhar nach ndéantar aon athrú orthu trí ama nó spás. Mar shampla, luas solais agus luas spreagtha de bharr gaiteasa. Dáil siúnáil tábhachtach is time-varying nó space-varying, ciallmhar go ndéantar aon athrú orthu trí ama nó spás. Mar shampla, fuaim ghutha agus voltage bataery suntar siúnáil time-varying.
Dáil siúnáil tábhachtach is periodic, ciallmhar go ndéantar aon athrú orthu trí ama nó spás. Mar shampla, teocht seomra thar lá amháin suntar siúnáil periodic, toisc go ndéantar aon athrú orthu gach 24 uair an chloig. Dáil siúnáil tábhachtach is non-periodic, ciallmhar nach ndéantar aon athrú orthu trí ama nó spás. Mar shampla, fuaim ghutha suntar siúnáil non-periodic, toisc nach raibh aon patrún daingnithe agus aon athrú déantar orthu.
Is síniúil wave signal cineál speisialta siúnáil periodach atá le smacht agus oscillation repetitive. Tá sé bunaithe ar sine nó cosine trigonometric function, a léiríonn an curv an wave. An graif thíos léiríonn sampla de shíniúil wave signal.
Is féidir síniúil wave signal a léiriú matamaiticiúil mar:
y(t)=Asin(2πft+φ)=Asin(ωt+φ){\displaystyle y(t)=A\sin(2\pi ft+\varphi )=A\sin(\omega t+\varphi )}
ar:
y(t) is the value of the signal at time t
A is the amplitude of the signal, which is the maximum deviation from zero
f is the frequency of the signal, which is the number of cycles per second
ω= 2πf is the angular frequency of the signal, which is the rate of change of the angle in radians per second
φ{\displaystyle \varphi }is the phase of the signal, which is the initial angle at time t= 0
The frequency and angular frequency determine how fast the signal oscillates. A higher frequency or angular frequency means more cycles in less time, and vice versa. The phase determines when the signal starts its cycle. A positive phase means an advance in time, and a negative phase means a delay in time.
A sinusoidal wave signal completes one cycle when it goes from zero to positive peak to zero to negative peak, and back to zero. The duration of one cycle is called the period (T) of the signal, which is inversely proportional to the frequency:
T=1/f{\displaystyle T=1/f}
The distance between two consecutive peaks or troughs is called the wavelength (λ) of the signal, which is inversely proportional to the angular frequency:
λ=2π/ω{\displaystyle \lambda =2\pi /\omega }
The shape of a sinusoidal wave signal does not change when it is added to another sinusoidal wave signal of the same frequency and arbitrary amplitude and phase. This property makes sinusoidal wave signals useful for analyzing complex signals using the Fourier series and Fourier transform.
Sinusoidal wave signals are important for many applications in electrical and electronic engineering domains. Some of the major applications are:
Audio systems use sinusoidal wave signals to record and reproduce sound. Sound waves are variations in air pressure that can be represented as sinusoids of different frequencies and amplitudes. Microphones convert sound waves into electrical sinusoidal signals, which can be amplified, processed, stored, or transmitted. Speakers convert electrical sinusoidal signals back into sound waves by vibrating a diaphragm. We can also synthesize sound by using electronic oscillators to generate sinusoidal signals of desired frequencies and amplitudes.
Wireless communication systems use sinusoidal wave signals to transmit and receive information over electromagnetic waves. Electromagnetic waves are composed of sinusoidally oscillating electric and magnetic fields that propagate through space. Radio systems modulate the amplitude, frequency, or phase of a sinusoidal carrier signal with the information signal to encode the data. The modulated signal is then amplified and radiated by an antenna. The receiver antenna captures the electromagnetic wave and demodulates the signal to recover the information.
Power systems use sinusoidal wave signals to generate and distribute electrical power. Sinusoidal AC voltage has the advantage of being easily transformed to different voltage levels by using transformers. This facilitates the transmission of power over long distances with minimal losses. Most power generators produce sinusoidal AC voltage by rotating a coil in a magnetic field or vice versa. Most household appliances and industrial equipment also operate on sinusoidal AC voltage.
The signal analysis uses sinusoidal wave signals to simplify the mathematical representation and manipulation of complex signals. According to the Fourier series and Fourier transform, any periodic or non-periodic signal can be decomposed into a sum of sinusoidal signals of different frequencies, amplitudes, and phases. This allows us to analyze the frequency spectrum, harmonic content, power, bandwidth, and other properties of a signal using simple algebraic operations.