# MODAM

## Purpose:

Performs amplitude modulation of a series.

## Syntax:

MODAM(series, fc)

series |
- |
A series, the input to modulate. |

fc |
- |
Optional, a real. The
carrier frequency. Defaults to **rate(series)/4**. |

## Returns:

A series, the amplitude modulated output.

## Example:

W1: gtriwave(1000,.001, 4)

W2: modam(w1, 200)

W3: demodam(w2, 200)

W4: specgram(w2, 64, 63, 1024)

The triangle series of W1 is amplitude
modulated with a carrier frequency of 200 Hz in W2. W3 recovers the modulated
series and W4 displays the joint time-frequency plot of the
frequency modulated series.

## Example:

W1: gtriwave(1000,.001, 4)

W2: modam(w1, 300)

W3: demodam(w2, 300)

W4: specgram(w2, 64, 63, 1024)

Same as above except
the carrier frequency is 300 Hz.

## Remarks:

The carrier frequency should be greater
than or equal to the bandwidth of the input series but less than or equal
to **rate(series) / 2**, the Nyquist
frequency.

See DEMODAM
to demodulate an amplitude modulated series.

See MODFM
to frequency modulate a series.

## See Also:

DEMODAM

DEMODFM

MODFM