Why are “square law” devices important?
Clash Royale CLAN TAG#URR8PPP
$begingroup$
In the literature, I often see the notion of square law devices. Why are these devices important, to the extent that they have their own characterization as square law device?
In what context does this square law property become relevant, except the fact that it characterizes the relationship between an input and an output parameter for that device.
photodiode device
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
$endgroup$
add a comment |
$begingroup$
In the literature, I often see the notion of square law devices. Why are these devices important, to the extent that they have their own characterization as square law device?
In what context does this square law property become relevant, except the fact that it characterizes the relationship between an input and an output parameter for that device.
photodiode device
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
$endgroup$
1
$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
4
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52
add a comment |
$begingroup$
In the literature, I often see the notion of square law devices. Why are these devices important, to the extent that they have their own characterization as square law device?
In what context does this square law property become relevant, except the fact that it characterizes the relationship between an input and an output parameter for that device.
photodiode device
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
$endgroup$
In the literature, I often see the notion of square law devices. Why are these devices important, to the extent that they have their own characterization as square law device?
In what context does this square law property become relevant, except the fact that it characterizes the relationship between an input and an output parameter for that device.
photodiode device
photodiode device
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
asked Feb 21 at 18:39
Kristof TakKristof Tak
2631714
2631714
1
$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
4
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52
add a comment |
1
$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
4
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52
1
1
$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
4
4
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52
add a comment |
3 Answers
3
active
oldest
votes
$begingroup$
It's a particular classification of nonlinear behavior that has important applications.
In the same way as you can consider, say, a BJT as linear over a limited range, you can consider something like a diode as square law over a limited range. That simplification allows you to analyze functions such as RF detectors analytically.
See, for example, this Agilent paper "Square Law
and Linear Detection".
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
$endgroup$
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
add a comment |
$begingroup$
Electronic things that follow square laws:
power loss with distance over the air aka "Friis Loss" for RF due to power is spread by broadcast over beam width arc path at a distance is proportional to $r^2$
- the same is true with optical communication, sound and other signal sources like WiFi when there are no reflections of obstacles.
power loss in conductors from Ohm's Law, $V=IR$ we get $Pd = VI = V^2/R = I^2R$
- diode impedance = voltage/current for small ac signals with Vdc bias before saturation at rated current, then it becomes linear
- reverse diode capacitance vs voltage. C is maxed at 0V and reduces by k*V² at rated reverse Vr and C(0V) is a function of rated power and 1/Rs the linear saturation resistance in forward bias. Varicaps are controlled diodes for specific square law VCO tuning with C ratios given at 2 voltages.
- because of diode square law when used in negative feedback can be used as "analog signal "multipliers" or converting the voltage to power.
Fundamentally, based on the geometry of a 2D circle $C=pi R^2$ then we have cubic laws based on 3D geometry of a sphere and higher orders that describe laws of nature.
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
$endgroup$
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
add a comment |
$begingroup$
Square Law devices make excellent RF mixers. A perfect square law device produces only the Sum and the Difference outputs.
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
$endgroup$
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
It's a particular classification of nonlinear behavior that has important applications.
In the same way as you can consider, say, a BJT as linear over a limited range, you can consider something like a diode as square law over a limited range. That simplification allows you to analyze functions such as RF detectors analytically.
See, for example, this Agilent paper "Square Law
and Linear Detection".
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
$endgroup$
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
add a comment |
$begingroup$
It's a particular classification of nonlinear behavior that has important applications.
In the same way as you can consider, say, a BJT as linear over a limited range, you can consider something like a diode as square law over a limited range. That simplification allows you to analyze functions such as RF detectors analytically.
See, for example, this Agilent paper "Square Law
and Linear Detection".
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
$endgroup$
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
add a comment |
$begingroup$
It's a particular classification of nonlinear behavior that has important applications.
In the same way as you can consider, say, a BJT as linear over a limited range, you can consider something like a diode as square law over a limited range. That simplification allows you to analyze functions such as RF detectors analytically.
See, for example, this Agilent paper "Square Law
and Linear Detection".
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
$endgroup$
It's a particular classification of nonlinear behavior that has important applications.
In the same way as you can consider, say, a BJT as linear over a limited range, you can consider something like a diode as square law over a limited range. That simplification allows you to analyze functions such as RF detectors analytically.
See, for example, this Agilent paper "Square Law
and Linear Detection".
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
answered Feb 21 at 18:48
Spehro PefhanySpehro Pefhany
210k5162425
210k5162425
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
add a comment |
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
7
7
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
$begingroup$
Similarly, the OP could have also replaced "square law devices" with "linear devices" into his question and the basic answer would essentially be the same.
$endgroup$
– Toor
Feb 21 at 18:50
3
3
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
$begingroup$
That app note is still "in print" from Broadcom. Though they haven't bothered to re-badge it from Avago. (And HP versions of it are also out there on the net)
$endgroup$
– The Photon
Feb 21 at 19:25
add a comment |
$begingroup$
Electronic things that follow square laws:
power loss with distance over the air aka "Friis Loss" for RF due to power is spread by broadcast over beam width arc path at a distance is proportional to $r^2$
- the same is true with optical communication, sound and other signal sources like WiFi when there are no reflections of obstacles.
power loss in conductors from Ohm's Law, $V=IR$ we get $Pd = VI = V^2/R = I^2R$
- diode impedance = voltage/current for small ac signals with Vdc bias before saturation at rated current, then it becomes linear
- reverse diode capacitance vs voltage. C is maxed at 0V and reduces by k*V² at rated reverse Vr and C(0V) is a function of rated power and 1/Rs the linear saturation resistance in forward bias. Varicaps are controlled diodes for specific square law VCO tuning with C ratios given at 2 voltages.
- because of diode square law when used in negative feedback can be used as "analog signal "multipliers" or converting the voltage to power.
Fundamentally, based on the geometry of a 2D circle $C=pi R^2$ then we have cubic laws based on 3D geometry of a sphere and higher orders that describe laws of nature.
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
$endgroup$
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
add a comment |
$begingroup$
Electronic things that follow square laws:
power loss with distance over the air aka "Friis Loss" for RF due to power is spread by broadcast over beam width arc path at a distance is proportional to $r^2$
- the same is true with optical communication, sound and other signal sources like WiFi when there are no reflections of obstacles.
power loss in conductors from Ohm's Law, $V=IR$ we get $Pd = VI = V^2/R = I^2R$
- diode impedance = voltage/current for small ac signals with Vdc bias before saturation at rated current, then it becomes linear
- reverse diode capacitance vs voltage. C is maxed at 0V and reduces by k*V² at rated reverse Vr and C(0V) is a function of rated power and 1/Rs the linear saturation resistance in forward bias. Varicaps are controlled diodes for specific square law VCO tuning with C ratios given at 2 voltages.
- because of diode square law when used in negative feedback can be used as "analog signal "multipliers" or converting the voltage to power.
Fundamentally, based on the geometry of a 2D circle $C=pi R^2$ then we have cubic laws based on 3D geometry of a sphere and higher orders that describe laws of nature.
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
$endgroup$
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
add a comment |
$begingroup$
Electronic things that follow square laws:
power loss with distance over the air aka "Friis Loss" for RF due to power is spread by broadcast over beam width arc path at a distance is proportional to $r^2$
- the same is true with optical communication, sound and other signal sources like WiFi when there are no reflections of obstacles.
power loss in conductors from Ohm's Law, $V=IR$ we get $Pd = VI = V^2/R = I^2R$
- diode impedance = voltage/current for small ac signals with Vdc bias before saturation at rated current, then it becomes linear
- reverse diode capacitance vs voltage. C is maxed at 0V and reduces by k*V² at rated reverse Vr and C(0V) is a function of rated power and 1/Rs the linear saturation resistance in forward bias. Varicaps are controlled diodes for specific square law VCO tuning with C ratios given at 2 voltages.
- because of diode square law when used in negative feedback can be used as "analog signal "multipliers" or converting the voltage to power.
Fundamentally, based on the geometry of a 2D circle $C=pi R^2$ then we have cubic laws based on 3D geometry of a sphere and higher orders that describe laws of nature.
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
$endgroup$
Electronic things that follow square laws:
power loss with distance over the air aka "Friis Loss" for RF due to power is spread by broadcast over beam width arc path at a distance is proportional to $r^2$
- the same is true with optical communication, sound and other signal sources like WiFi when there are no reflections of obstacles.
power loss in conductors from Ohm's Law, $V=IR$ we get $Pd = VI = V^2/R = I^2R$
- diode impedance = voltage/current for small ac signals with Vdc bias before saturation at rated current, then it becomes linear
- reverse diode capacitance vs voltage. C is maxed at 0V and reduces by k*V² at rated reverse Vr and C(0V) is a function of rated power and 1/Rs the linear saturation resistance in forward bias. Varicaps are controlled diodes for specific square law VCO tuning with C ratios given at 2 voltages.
- because of diode square law when used in negative feedback can be used as "analog signal "multipliers" or converting the voltage to power.
Fundamentally, based on the geometry of a 2D circle $C=pi R^2$ then we have cubic laws based on 3D geometry of a sphere and higher orders that describe laws of nature.
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
edited Feb 22 at 2:41
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
answered Feb 21 at 18:49
Sunnyskyguy EE75Sunnyskyguy EE75
69k22598
69k22598
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
add a comment |
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
$begingroup$
TY @VolkerSiegel for edits
$endgroup$
– Sunnyskyguy EE75
Feb 22 at 2:42
add a comment |
$begingroup$
Square Law devices make excellent RF mixers. A perfect square law device produces only the Sum and the Difference outputs.
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
$endgroup$
add a comment |
$begingroup$
Square Law devices make excellent RF mixers. A perfect square law device produces only the Sum and the Difference outputs.
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
$endgroup$
add a comment |
$begingroup$
Square Law devices make excellent RF mixers. A perfect square law device produces only the Sum and the Difference outputs.
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
$endgroup$
Square Law devices make excellent RF mixers. A perfect square law device produces only the Sum and the Difference outputs.
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
answered Feb 22 at 3:06
analogsystemsrfanalogsystemsrf
15.4k2722
15.4k2722
add a comment |
add a comment |
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$begingroup$
Please give a link to an example of the literature of which you speak, or provide much more detail about your question.
$endgroup$
– Elliot Alderson
Feb 21 at 18:40
4
$begingroup$
It's just a common trait in a bunch of things so rather than explain them one-by-one piecemeal you just group them together so you can talk about them all at once. It's like asking "why the notion of circular motion so important to the extent that it has its own set of equations?" You can apply the same concepts to a bunch of different things, so you just group them together with a label. In that sense, there is nothing beyond it being relevant except for the fact that it characterizes a common input-output relationship.
$endgroup$
– Toor
Feb 21 at 18:47
$begingroup$
The ability to convert a squiggly line on a graph to numbers/variables is invaluable in analyzing, characterizing, understanding, and simplifying the transfer function (aka output/input). For instance, when building more complicated circuits, would you rather combine a bunch of input/output graphs together to understand the final output or combine mathematical descriptions of it like (x-2)^2 and (y+2)^2 ?
$endgroup$
– horta
Feb 21 at 21:52