# File:Phase shifter using IQ modulator.gif

Original file(842 × 380 pixels, file size: 1.57 MB, MIME type: image/gif, looped, 72 frames, 8.6 s)

## Summary

 Description English: Phasor and wave diagram animation showing how phase change is achieved in I+Q signal by changing I (inphase cosine component) and Q (quadrature sine component) signals amplitude in IQ modulators. For Python code used to generate this image, go to the image file description page by clicking "More details" button. Date 2 February 2020 Source Own work Author Vigneshdm1990

## Source code Python Matplotlib

The following python code is used to generate 72 images used in this animation. Then using an online gif image maker "ezgif.com" these 72 images are combined to get gif image.

```# Python code using matplotlib library to generate 72 images to create a gif file that shows
# how phase change is achieved by changing I and Q signals amplitude in IQ modulators
#

# Physics concept : how by only changing the magnitude of I and Q signals amplitude
# one can change the phase of I+Q wave signal

import matplotlib.pyplot as plt
import numpy as np

# t is the current phase, and phase is changed from 0° to 355° in the steps of 5°

for t in range(0,356,5):

# I) CREATING FUNCTION FOR PLOTTING

# creating a blue circle in PHASOR DIAGRAM using parametric equation (radius=1, theta=s)
s=np.linspace(0, 2 * np.pi, 400)
x1=np.cos(s)
y1=np.sin(s)

# creating I and Q vectors magnitude (x=I, y=Q) in PHASOR DIAGRAM
x = 1*np.cos(0.0174533*t)
y = 1*np.sin(0.0174533*t)

# creating I, Q, I+Q amplitude and Phase (0° to 720°) for WAVE DIAGRAM
x2 = np.linspace(0, 721, 400) # Pahse from 0° to 720° divided into 400 points
y2 = 1*np.sin(0.0174533*t)*np.sin(0.0174533*x2) # Q
z2 = 1*np.cos(0.0174533*t)*np.cos(0.0174533*x2) # I
q2 = (y2 + z2) # (I+Q)

# creating text to show current phase t
text1 = "phase = " + str(t)+'°'

# II) CREATING THE PLOT (phasor and wave diagram in one plot arranged 1 x 2)

# ax1 = Phasor diagram subplot and ax2 = Wave diagram subplot
fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(9.5,4.1))
ax1.title.set_text('Phasor diagram')
ax2.title.set_text('Wave diagram')

# Setting the position of the subplot title
ax1.title.set_position([.5, 1.05])
ax2.title.set_position([.5, 1.05])

# II-A) PHASOR DIAGRAM

# including the current phase inside the Phasor diagram subplot
ax1.text(0.9, 0.9, text1, bbox=dict(boxstyle="square",facecolor='white', alpha=0.5))

# setting the y axis limit
ax1.set_ylim(-1, 1)

# Plotting the blue outer circle of radius = 1
ax1.plot(x1, y1, 'b')

# Move left y-axis and bottom x-axis to centre, passing through (0,0)
ax1.spines['left'].set_position('center')
ax1.spines['bottom'].set_position('center')

# Eliminate upper and right axes
ax1.spines['right'].set_color('none')
ax1.spines['top'].set_color('none')

# Show ticks in the left and lower axes only
ax1.xaxis.set_ticks_position('bottom')
ax1.yaxis.set_ticks_position('left')

# Setting the y axis ticks at (-1,-0.5,0,0.5,1)
ax1.set_yticks([-1,-0.5,0,0.5,1])

# Creating Arrows and dashed lines

# II-B) WAVE DIAGRAM

# setting the y axis limit
ax2.set_ylim(-1.5, 1.5)

# Setting the y axis ticks at (0, 180, 360, 540, 720) degree phase
ax2.set_xticks([0, 180, 360, 540, 720])

# Setting the position of the x and y axis
ax2.spines['left'].set_position(('axes', 0.045))
ax2.spines['bottom'].set_position(('axes', 0.5))

# Eliminate upper and right axes
ax2.spines['right'].set_color('none')
ax2.spines['top'].set_color('none')

# Creating x and y axis label

# Plotting I, Q and I+Q waves
ax2.plot(x2, z2, 'b', label='I', linewidth=0.5)
ax2.plot(x2, y2, 'r', label='Q', linewidth=0.5)
ax2.plot(x2, q2, 'g', label='I+Q')

# function for amplitude of I+Q green arrow
c1=1 * np.cos(0.0174533 * t) * np.cos(0.0174533 * t)+1*np.sin(0.0174533*t)*np.sin(0.0174533*t)

# plotting I+Q arrow that moves along to show the current phase

# plotting I and Q amplitude arrows at position 180° and 90° respectively

# Creating legend
ax2.legend(loc='center', ncol=3, bbox_to_anchor=[0.5, 0.94])

# Adjusting the relative position of the subplots inside the figure
fig.subplots_adjust(left=0.07, bottom=0.15, right=None, top=None, wspace=0.3, hspace=None)

# Saving the figure
fig.savefig('0file%s.png' %t)

# Clearing the figure for the next iteration
fig.clf()
```

## Licensing

I, the copyright holder of this work, hereby publish it under the following license:   This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. You are free: to share – to copy, distribute and transmit the work to remix – to adapt the work Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

### Captions

Animation of a phase shifter using IQ modulator. By changing the amplitude of I and Q waves one can change the phase of the I+Q wave.

### Items portrayed in this file

#### source of file

current21:26, 2 February 2020 842 × 380 (1.57 MB)Vigneshdm1990User created page with UploadWizard