Chip vs Whip antenna

[arhi]

Chip vs Whip antenna... the data sheet for the XBEE module (XBP24-AWI vs XBP24-ACI) don't say if there's a difference (or I was unable to find it)... any comments on chip vs whip .. in terms of "anything" .. (power consumption, range, sensitivity ...) as if the chip antenna is "as good as the whip one" ... I do not see the reason for the whip one

 

[JimB]

I found the following information in this datasheet:
https://www.electro-tech-online.com/custompdfs/2009/03/manual_xb_oem-rf-modules_802154_v1xAx.pdf

****************************************************

XBee-PRO OEM RF Module

[FONT=Verdana,Verdana][FONT=Verdana,Verdana](@ 10 dBm Transmit Power, PL parameter value must equal 0) [/FONT][/FONT][FONT=Verdana,Verdana]
[FONT=Verdana,Verdana]The following antennas have been tested and approved for use with the embedded XBee-PRO RF Module: [/FONT]
[FONT=Verdana,Verdana]• Dipole (2.1 dBi, Omni-directional, Articulated RPSMA, MaxStream part number A24-HABSM) [/FONT]
[FONT=Verdana,Verdana]• Chip Antenna (-1.5 dBi) [/FONT]
[FONT=Verdana,Verdana]• Attached Monopole Whip (1.5 dBi) [/FONT]
[FONT=Verdana,Verdana]The RF modem encasement was designed to accommodate the RPSMA antenna option. [/FONT]
*****************************************************

So the chip antenna has a gain of -1.5dBi, and the whip antenna has a gain of +1.5dBi.

What this means is that there is a difference of 3dB beteween them, the whip antenna is superior by a factor of 2 in terms of transmitted and recieved signal power.

JimB
[/FONT]
​

 

[Sceadwian]

Don't over look the dipole option, with an extra .6dbi isn't too shabby. Making a dipole for it shouldn't be too hard. Out of curiosity what's the directionality of those chip antennas?

 

[RadioRon]

Most of them are linearly polarized in the plane of the pcb and working against the large pcb area as a counterpoise, so it would have the typical donut pattern that you might get from a typical monopole, only it is lying on its side and would be horizontally polarized. If you orient the module vertically, then it would come close to matching the pattern of the little whip antenna on the other version.

 

[duffy]

The chip antenna is made by Fractus, that Sierpinski Triangle is their logo.
Fractus – world leader in fractal antenna IP and licensing

I've always been a little skeptical of "fractal antennas", and that 50% power reduction going from a whip to a chip isn't helping my skepticism.

 

[arhi]

I never tried "chip antenna" and somehow missed the -1.5dbi vs 1.5dbi... actually - I have not seen it in original xbee doc's even after JimB's post. JimB THANKS for that link cleared up few things in my head.

Sceadwian, thx but no thx ... for this I am only interested in "ready made" solution .. no "adaptations" ..

diffy, thx for explanation .. never used chip antenna link is interesting but I'm going with whip

 

[Sceadwian]

arhi, if a dipole is an 'adaptation' as you call it, why is it listed first on the antenna specs for that module with the highest gain of all three antenna configs?

 

[arhi]

sceadwian, sorry when you said dipole I immediately imagined making my own ...

the modules come in 3 "ways"
- chip
- whip
- connector

there is a number of antennas you can connect to connector and they do offer more then chip/whip one .. but, then the whole thing becomes more complex (mounting the antenna etc)

I'm still deciding on how to proceed to the wireless realm .. the BT is too expensive, xbee loks like the right way to go .. with pro and non pro being interchangeable .. that might be the good option ... (pro use much more power but has longer range)... still considering the microchip solution ... the free time is limited now so I'm using it to get as much info as I can before I have free time to test .. (so I then spent right amount of money for testing and not too much as usual )

 

[3v0]

I am going to give the MRF24J40MA's a try. It uses a PCB antenna on the module but you need to supply a ground plane on your PCB.

They claim a range of up to 400 feet. I need half that.

3v0

 

[arhi]

3v0, I tought about it .. the 4layer pcb made me forget about the MRF24J40MA and go for "ready made stuff" .. the **broken link removed** (microchip daughter board with MRF24J40MA) is 39.00US$ locally, and zigbee (fully assembled with serial interface towards you) is 23.85US$ - 35.64US$ depending on the model (xbee, xbee series2, xbee pro) ... it is simple choice for me at the end ... it "just works" and it is cheaper to go with xbee modules.

I see here: https://www.electro-tech-online.com/custompdfs/2009/03/PICDEM20Z20Users_Guide_51524C.pdf the veri simple "MRF24J40MA PICDEMTM Z 2.4 GHz RF BOARD" 2 side pcb ... will have to investigate .. looks interesting

 

[Mike_2545]

I just got a pair of XBee delivered Friday! Won't have time to play with them till next week but it looks straight forwardower and a serial line (on in and one out) is all you need. Of course there plenty of options to explore inside the chip.

I went for the chip antenna.

Don't yet have an application for them, just wanted to see what they can do.

 

[arhi]

I got the BT module (parani sena esd110 ..) to "play with" tried it out, found it is very easy to use but expensive

then I got some 200-500MHz RF modules (AM and FM) ... tried them out and found out that 20-30$ is too much for them too

now want to try out the xbee & MRF24J40* but wanted to check for more info before I make a purchase ... I do not have time now nor will I have in next month or so to play with them so .. (spent NY holidays playing with BT but some private problems limited that time too )

The problematic part is "I do not need it", for 99.9% of what I make IR is more then enough, so I do not have "requirements" .. that leaves too many things open so I'm looking for "virtually" best thing for the "virtual" job

I was also thinking of going with chip antenna but that 3db difference convinced me otherwise

 

[Sceadwian]

If you can physically afford the space a whip is your best bet if you just want to buy the module ready made without dealing with your own antenna, but there is something to be said for the size.

 

[arhi]

Sceadwian I agree with you 100% .. the "no requirements" is making the things difficult I will go with whip antenna for now .. the space is plentiful on the breadboard

thanks for sharing

 

[3v0]

What I ordered was the MRF24J40MA module **broken link removed****broken link removed**.
It still requires a PIC to run the stack but the TX RX are ready to go. I know you may not be able to buy from Newark but they have them for $10 US each (and only 17 in stock). MICROCHIP|MRF24J40MA-I/RM|2.4 GHz IEEE 802.15.4 Transceiver | Newark.com

I think the 2 sided board in the appnote is for a mainboard that the 4 layer rf board MRF24J40MA connects to. Which is what I would need to make.

The Xbee does have a big advantage in that you do not have to mess with the stack.

3v0

 

[DirtyLude]

That MicroChip module looks really good. Digikey has them for $10.00 as well. I'm definitely going to be ordering 2 on my next order and see what I can do with them.

 

[arhi]

I do not have big problem messing with the stack .. will check if local distributor (they are "partners" with microchip .. so they should have them) sell the mrf24j40ma module or at least a chip ...

 

[3v0]

I do not have big problem messing with the stack .. will check if local distributor (they are "partners" with microchip .. so they should have them) sell the mrf24j40ma module or at least a chip ...

I have mixed feeling. In some ways it would be fun to play with etc. On the other hand it is one more thing in a long list of projects that I want/need to do.

I guess it all depends on which side of the bed I get up on

 

[arhi]

I ordered 2x MRF24J40MA (15$ each) and 2x XBP24-BWIT (40$ each)

so ... I have 2 without stack and 2 with znet stack (p2p, p2mp, mesh.. blah blah ..) should be more then enough for testing ... and if I make the MRF24J40MA easily talk to XBP24-BWIT without killing the uC .. that's gonna be ideal