example by ADS for rectenna

[saqly]

please i need help in rectenna, if any body have example by ADS for rectenna i need it for my graduated project.or anybody have a
PDF or video for design rectenna by ADS from start to end.

 

[andre_luis]

Re: rectenna design RF energy harevesting

Curiously, someone is asking the same thing for the same purpose :

https://www.edaboard.com/threads/304648/#post1304208


+++

 

[saqly]

Re: rectenna design RF energy harevesting

i need example or how do example rectenna in ADS

 

[adnan19888]

Re: rectenna design RF energy harevesting

hi is anyone working on Rectenna system and can share details on his design? Anyone has HFSS simulation?

 

[saqly]

Re: rectenna design RF energy harevesting

hi i need design rectenns in ADS simulation pleases

 

[WimRFP]

Re: rectenna design RF energy harevesting

i need example or how do example rectenna in ADS

What is your goal, showing something designed by others, or doing the design yourself and learn from it? I would recommend you to do some search yourself (also here) and than come back with specific questions. Some things that may be of importance:

-frequency range of EM field that you want to harvest,
-relative bandwidth of EM field (has large influence on matching towards the rectifier).
-Omni-directional or directional receiving antenna,
-Polarization of EM field to be received,
-expected received power,
-required output voltage/current after rectification,
-(almost) CW fields or fields with high peak/average ratio, etc

Make sure you have a simulator that can do non-linear simulations as the rectifiers are operating in its non-linear region. You may separate the antenna design from the matching/diode section, so the antenna design you can do in a linear EM simulator. Make a lumped circuit model of your antenna and do the rectifier/matching in a lumped circuit non-linear simulator (spice?).

 

[saqly]

Re: rectenna design RF energy harevesting

frequency : 2.45GHZ
BW : 2.4-2.5 GHZ
Omni-directional
power 50 mw
voltage 3.7v current 150mA

i need rectenna to charge battery of mobile not all battery but some of batteries.

 

[WimRFP]

Re: rectenna design RF energy harevesting

First, start with some antenna theory (for example the Friis formula and why the formale is as it is). You also should know: reactive field zone, transition field zone (Fresnel region), far field zone (Fraunhofer region).

This will give you some idea what is possibie. You will discover that what you want is very likely not feasible for a practical application.

 

[saqly]

Re: rectenna design RF energy harevesting

i try charge mobile using radio frequency by Rectenna

 

[WimRFP]

Re: rectenna design RF energy harevesting

As I mentioned in #8, go through the process of calculating the maximum power that you can "extract" from the air in your frequency band. After rectification, you will have less DC power of course. This may not harm your project, but it is very likely not possible to charge a mobile phone.

 

[saqly]

Re: rectenna design RF energy harevesting

i am not understanding all things please i need a way for charge any electronic devices mp3,mp4 anything
i ask how collect power from air to charge its

 

[Audioguru]

Re: rectenna design RF energy harevesting

You might be lucky and have a very high power radio transmitter nearby.
But it is likely you will harvest only enough energy to run a low power LCD watch, not charge a phone.

 

[WimRFP]

Re: rectenna design RF energy harevesting

@sagly: Now you changed your question (see #11). As Audioguru said, you need to find a high power radio transmitter in your vicinity (likely broadcast) or cell phone.

Then you need to measure the fieldstrength at the rectenna's position. This you can convert into a plane wave power flux density (in W/m2). This will give you some idea of what power you can extract with a certain size of antenne.

When (for example) the plane wave power flux density is 1 mW/m^2, you need at least an antenna with a physical size of at least 10 m^2 to extract 10 mW of RF signal out of the air.

 

[saqly]

Re: rectenna design RF energy harevesting




this power is AC or DC , these power is output recteenna

 

[WimRFP]

Re: rectenna design RF energy harevesting

In a simulator you can put in everything you want, you can even modify a diode model to get zero capacitance and infinite breakdown voltage and you can simulate kW of DC output, however does it have any relation with reality?

I don't know the scope of your project, but if you want something that does the job in real world, you should work with real world variables. That requires some investigation and study, but that is part of developing yourself. No matter the outcome of the project, taking the required steps to find answers will help you further in electroncs and RF design.

 

[kela3kela]

Can someone plz refer some papers or books that mention the formulas on HOW to calculate Em wave conversion by rentenna to an output voltage.

E.g. Let say at 900 MHz the obtained output dc voltage is 3.2V. How to calculate this voltage?? mathematical formulas please..

 

[WimRFP]

There are many people that can mention formulas, but how do you know whether or not they are applicable to your situation?

I think it is good to take some time to familiarize yourself with some antenna basics. Something you may encounter:
-Power flux density (W/m2) and E-field (V/m)
-effective capture area of an antenna
-Friis formula
-two ray formula
-Gain and Directivity
-Impedance transformation or matching.

Basically a transmitter produces a certain power flux density at certain distance (U, expressed in W/m2).

An antenna has a certain "capture area" or "effective area", Ae, expressed in m2. For antennas that don't use strong resonance, there is some relation between the effective area and the physical size or area.

The extracted power from the air equals:

PRX = Ae*U [W], PRX = power extraced from the air and delivered to the load (here your matching circuit with rectifier).

During your study you will find that:

U = E^2/377 [W/m2] , E = electric fieldstrength in V/m

Ae = Gi*lambda^2/(4*pi) [m^2], where Gi is the isotropical gain (not in dB's) and lambda = wavelength in m

The well known half wave dipole has Gi=1.64
A full size patch antenna will have Gi = 6 (approximately).


For a free space situation: U = EIRP/(4*pi*r^2) [W/m2]
EIRP = equivalent isotropically radiated power = transmitter power * (Gi) of transmitter antenna), in W
r = distance between transmitter and receive antenna in m.

In real world the power flux density can be less (and sometimes more) due to destructive or constructive reflection at mother earth, and obstacles. For good understanding of such propagation issues you may study some Fresnel diffraction applied to radio wave propagation, but I think that may be beyond what you need.

Once you have some received power, you need matching and filtering to make sure that the rectifier operates at its highest efficiency.

 

[kela3kela]

Thanks for the detailed explanation. It is very helpful as a beginning step.

 

[samsoun]

Hello,
i design an rectenna System using ads 2009, i used double voltage rectifier circuit with Schottky diode HSMS2852. But i dont know how to calculate Z load using S parameters for the impedance matching.

 

[WimRFP]

You are probably aware that the rectifier is a non-linear circuit, so:
-Harmonics will be generated, even with a pure sinusoidal excitation.
-Input impedance for the first harmonic components may be dependent on how the harmonics are terminated.
-Input impedance for the first harmonic components depend on the level of the excitation and the DC load impedance.

You could run a full EM mixed non-linear simulation (if your simulator allows this), but this may take lots of time.


I would use a two-step approach:
Use a non-linear network simulation (spice, harmonic balance) to design the rectifier. Include some filtering to avoid that harmonics reach the antenna (as they will be reradiated). S11 of your rectifier circuit you can determine based on the impedance for the first harmonic voltage and current components at intended DC load resistance and RF input level.

Don't forget to first figure out how much power you can extract from the air for your application!