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RF Filter PCBs
If you need to prototype or build a lumped element RF filter, check
out the RF Filter PCBs at RF Bites. http://www.rfbites.com |
RF Filter PCBs
On Nov 3, 5:49 pm, Telamon
wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California So, what material do you use over 1GHz? You buget guy must really not like you. BTW, I didn't design these boards, nor to I work for these guys. I just got my board in the other day and was pumped up when I was able to build up a filter quickly. It's in my tuner right now, filtering away. My filter has good rejection (50dB) up to 3.5GHz, and it starts to fall apart. |
RF Filter PCBs
On Nov 3, 5:49 pm, Telamon
wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. |
RF Filter PCBs
On Nov 3, 6:17 pm, wrote:
On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. Telamon, I would be glad to send you a spaned out response from the Net A. Let me know. FH |
RF Filter PCBs
In article . com,
wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. So, what material do you use over 1GHz? Commercially you could use Rogers materials. A good step over FR4 would be Rogers 4003. More expensive that that would be Rogers 5880. Comparable to Rogers 5880 would be 25N Arlon. You buget guy must really not like you. The bean counters don't like me at all. BTW, I didn't design these boards, nor to I work for these guys. I just got my board in the other day and was pumped up when I was able to build up a filter quickly. It's in my tuner right now, filtering away. My filter has good rejection (50dB) up to 3.5GHz, and it starts to fall apart. Your insertion loss will not be good over 1 GHz. Sure the filter will work over 1 Ghz. If you have a fast enough TDR you can see that that connector is very capacitive looking where the pin is on the board and the return losses will not be good. Since you use them on both ends of the board you will get reflections between them. The footprint for the connector is as important as the connector itself. -- Telamon Ventura, California |
RF Filter PCBs
In article . com,
wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. I would not use FR4 over 1GHz. -- Telamon Ventura, California |
RF Filter PCBs
On Sun, 04 Nov 2007 00:17:26 -0000, wrote:
On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4 |
RF Filter PCBs
On Nov 5, 5:21 am, David wrote:
On Sun, 04 Nov 2007 00:17:26 -0000, wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4- Hide quoted text - - Show quoted text - David - Good Info and Link. ~ RHF |
RF Filter PCBs
On Nov 5, 6:21 am, David wrote:
On Sun, 04 Nov 2007 00:17:26 -0000, wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4- Hide quoted text - - Show quoted text - Hi David, Good article. I partially agree with Talamon that FR4 is not ideal over 1GHz, if you have the budget for Roger's material and the specs that necessitate such performance in your substrate. In the commercial world, you would have a hard time justifying such an expense, so most designers have to eat the performance issues and work a little harder to develop more robust designs to handle the gross tolerance swings. I would challenge anyone to find a PCS cell phone (1.9GHz) or a commercial GPS with Roger's material. When I said that the FR-4 material was good up to 3.5GHz, that means I am getting good rejection in my filters up to that frequency. I wouldn't design my passband to be anything much over 2 GHz. Isn't there a saying that goes something like, "Any average Engineer can design a $50,000 car, it takes a good Engineer to design a $15,000 car." Food for thought. FH |
RF Filter PCBs
In article ,
David wrote: On Sun, 04 Nov 2007 00:17:26 -0000, wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4 There are much better places to go on the Internet to read about PCB dielectrics then Wikipedia. You will notice that FR4 has a high dielectric constant together with a poor loss tangent means it is very lossy at high frequencies. -- Telamon Ventura, California |
RF Filter PCBs
In article om,
wrote: On Nov 5, 6:21 am, David wrote: On Sun, 04 Nov 2007 00:17:26 -0000, wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4- Hide quoted text - - Show quoted text - Hi David, Good article. I partially agree with Talamon that FR4 is not ideal over 1GHz, if you have the budget for Roger's material and the specs that necessitate such performance in your substrate. In the commercial world, you would have a hard time justifying such an expense, so most designers have to eat the performance issues and work a little harder to develop more robust designs to handle the gross tolerance swings. I would challenge anyone to find a PCS cell phone (1.9GHz) or a commercial GPS with Roger's material. When I said that the FR-4 material was good up to 3.5GHz, that means I am getting good rejection in my filters up to that frequency. I wouldn't design my passband to be anything much over 2 GHz. Isn't there a saying that goes something like, "Any average Engineer can design a $50,000 car, it takes a good Engineer to design a $15,000 car." Food for thought. You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. -- Telamon Ventura, California |
RF Filter PCBs
On Mon, 05 Nov 2007 18:08:00 -0000, wrote:
On Nov 5, 6:21 am, David wrote: On Sun, 04 Nov 2007 00:17:26 -0000, wrote: On Nov 3, 5:49 pm, Telamon wrote: In article .com, wrote: If you need to prototype or build a lumped element RF filter, check out the RF Filter PCBs at RF Bites. http://www.rfbites.com Those are not very good coax to PCB connectors. You can do better. Must be pretty low frequency stuff ( 1 GHz ) if you are using FR4. -- Telamon Ventura, California Connectors are rated to 12GHz. FR-4 is good up to 3.5GHz, then it starts to fall apart. http://en.wikipedia.org/wiki/FR4- Hide quoted text - - Show quoted text - Hi David, Good article. I partially agree with Talamon that FR4 is not ideal over 1GHz, if you have the budget for Roger's material and the specs that necessitate such performance in your substrate. In the commercial world, you would have a hard time justifying such an expense, so most designers have to eat the performance issues and work a little harder to develop more robust designs to handle the gross tolerance swings. I would challenge anyone to find a PCS cell phone (1.9GHz) or a commercial GPS with Roger's material. When I said that the FR-4 material was good up to 3.5GHz, that means I am getting good rejection in my filters up to that frequency. I wouldn't design my passband to be anything much over 2 GHz. Isn't there a saying that goes something like, "Any average Engineer can design a $50,000 car, it takes a good Engineer to design a $15,000 car." Food for thought. FH I cheat. Anatech makes my filters. |
RF Filter PCBs
On Mon, 05 Nov 2007 17:40:58 -0800, Telamon
wrote: You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. Series, shunt? |
RF Filter PCBs
In article ,
David wrote: On Mon, 05 Nov 2007 17:40:58 -0800, Telamon wrote: You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. Series, shunt? That's the wrong way to look at it. Coax cable and a micro-strip-line on a PCB are examples of transmission lines. -- Telamon Ventura, California |
RF Filter PCBs
On Wed, 07 Nov 2007 02:04:57 GMT, Telamon
wrote: In article , David wrote: On Mon, 05 Nov 2007 17:40:58 -0800, Telamon wrote: You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. Series, shunt? That's the wrong way to look at it. Coax cable and a micro-strip-line on a PCB are examples of transmission lines. Conductor = series Dielectric = shunt A transmission line is a bunch of capacitors and resistors. |
RF Filter PCBs
In article ,
David wrote: On Wed, 07 Nov 2007 02:04:57 GMT, Telamon wrote: In article , David wrote: On Mon, 05 Nov 2007 17:40:58 -0800, Telamon wrote: You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. Series, shunt? That's the wrong way to look at it. Coax cable and a micro-strip-line on a PCB are examples of transmission lines. Conductor = series Dielectric = shunt A transmission line is a bunch of capacitors and resistors. A transmission line can be visualized as a series of LC not RC circuits. -- Telamon Ventura, California |
RF Filter PCBs
Telamon wrote:
In article , David wrote: snip A transmission line is a bunch of capacitors and resistors. A transmission line can be visualized as a series of LC not RC circuits. Depending on physical scale, R or L may dominate in the models, please see: http://sigcon.com/Pubs/news/7_01.htm "chip-scale transmission lines" Regards, Michael |
RF Filter PCBs
In article ,
msg wrote: Telamon wrote: In article , David wrote: snip A transmission line is a bunch of capacitors and resistors. A transmission line can be visualized as a series of LC not RC circuits. Depending on physical scale, R or L may dominate in the models, please see: http://sigcon.com/Pubs/news/7_01.htm "chip-scale transmission lines" Classic transmission line theory is loss-less LC, which is a description of constrained path propagation. R is a parasitic in real life models not a part of the description of how the path theoretically functions. Transmission lines in semiconductors and the packages they go into have an extreme constraint placed upon them that does not occur any place else. As I stated earlier in the thread that was sniped out "You always have two major ways to lose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction." The conductor losses are due to the resistance heating of the conductor and the dielectric losses come from the electric field heating the dielectric. Both loss types are dissipative and increase with frequency. -- Telamon Ventura, California |
RF Filter PCBs
On Wed, 07 Nov 2007 17:51:20 -0800, Telamon
wrote: In article , David wrote: On Wed, 07 Nov 2007 02:04:57 GMT, Telamon wrote: In article , David wrote: On Mon, 05 Nov 2007 17:40:58 -0800, Telamon wrote: You always have two major ways to loose signal, which are conductor and dielectric in PCB and coax. Either type of loss can dominate depending on materials and construction. Series, shunt? That's the wrong way to look at it. Coax cable and a micro-strip-line on a PCB are examples of transmission lines. Conductor = series Dielectric = shunt A transmission line is a bunch of capacitors and resistors. A transmission line can be visualized as a series of LC not RC circuits. My point being it can be analyzed as a network of discrete components. |
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