This document proposes a system to automatically recharge mobile phones through microwave transmission as the phone is being used. The system would transmit microwave signals from an antenna along with voice signals. Mobile phones would require minor additions like a sensor, rectenna, and filter to receive the microwave energy and use it to charge the phone battery. This would eliminate the need for separate chargers and allow the phone to charge as it is being used through voice calls. Manufacturers could remove talk time and battery life from phone specifications as a result.

1. i
ABSTRACT
Mobile phones becoming a basic part of life, the recharging of mobile phone batteries
have always been a problem. The mobile phones vary in their talk time and battery
standby according to their manufacture and batteries. All these phones irrespective of
their manufacturer and batteries have to be put to recharge after the battery has drained
out. The main objective of this current proposal to make their charging of the mobile
phones independent of their manufacturer and battery make. A new proposal has been
made so as to make the recharging of the mobile phones is done automatically as you talk
in your mobile phone. This done by using microwaves.
The microwave signal is transmitted from the transmitter along with the message
signal using special kind of antennas called slotted waveguide antenna at a frequency is
2.45GHZ. There are minimal additions, which have to be made in the mobile handsets,
which are the addition of a sensor, a rectenna and a filter. With the above setup, the need
for separate chargers for mobile phones is eliminated and makes charging universal. Thus
the more you talk, the more is your mobile phone charge. With this proposal the
manufacturers would be able to remove the talk time and battery standby from their
phone specifications.

2. ii
CONTENTS
Title Page no.
Abstract i
Table of contents ii
List of figures iii
List of tables iv
1. Introduction 1
2. Electromagnetic Spectrum 2
2.1 Microwave Region 3
2.2 Frequency Selection 4
3. Wireless Power Transmission 5
3.1 Microwave Generator 6
3.2 Transmitting Antenna 6
4. Block Diagram 7
5. System Design 7
6. Transmitter Design 7
6.1 Magnetron and its Working 8
6.2 Slotted Waveguide Antenna 9
7. Receiver Design 9
7.1 Rectifying Antenna 10
7.2 Schottky Barrier Diode 11
8. Sensor Circuitry 12
9. Future Scope 13
10. Advantages 13
11. Disadvantages 13
12. Conclusion 14
13. References 15

3. iii
LIST OF FIGURES
Fig. no. Title name Page no.
2.1 Electromagnetic spectrum 3
2.2 Microwave Region 4
3.1 Power Transmission System Block Diagram 6
6.1 Magnetron 8
6.2 Resonant cavity magnetron oscillator 8
6.3 Slotted Waveguide Antenna 7
6.4 Waveguide 9
7.1 Rectenna 10
7.2 Rectenna circuitry 11
6.1 Sensor (LM2907) 12

4. iv
LIST OF TABLES
Table no. Title name Page no.
2.1 Frequency Ranges 5