Electronic oscillator with independent controls of variable capacities

Abstract

Electronic oscillator with independent controls of variable capacitances The present description relates to an electronic oscillator (100) comprising a resonator (102) coupled in parallel to at least one active circuit (104), the resonator comprising two electrodes (110, 112) coupled to separate variable capacitances (116, 118) forming a load capacitance of the electronic oscillator, and a control device (148) configured to independently control the values ​​of the variable capacitances. Figure for abstract: Figure 1

Description

Title of the invention: Electronic oscillator with independent controls of variable capacities Technical field

[0001] The present description relates generally to the field of electronic oscillators. Prior art

[0002] Electronic oscillators using quartz resonators are very widely used in SoCs (system on chip), microcontrollers, radio devices, etc., especially in the RF (radio frequency) field. The high quality factor and low intrinsic electrical resistance of quartz resonators allow them to maintain stable oscillation with low power consumption. An architecture often used for such oscillators corresponds to that of Pierce oscillators.

[0003] A fine adjustment of the oscillation frequency of such an oscillator is sometimes necessary, for example in certain systems such as UWB (Ultra Wide Band) systems allowing, among other things, precise localization of objects. This adjustment of the oscillation frequency is achieved by adjusting the value of a load capacitance coupled to the resonator of the oscillator. This load capacitance can be formed by several capacitors distributed in one or more capacitor banks. This or these capacitor banks can be integrated on a chip with the oscillator.

[0004] With existing oscillators, the greater the precision required for adjusting the value of the load capacitance, the greater the number of capacitors in the banks must be. For example, when the resonator used is of the piezoelectric MEMS type, the required value for the load capacitance is generally lower than for a quartz resonator. However, the lower the value of the load capacitance, the greater the variation in the oscillation frequency of the oscillator will be for a given variation in the load capacitance. This results in a precision of adjustment of the value of the load capacitance which must be greater. Summary of the invention

[0005] There is a need to propose an electronic oscillator which is compatible in particular with existing quartz and MEMS technologies and in which precise adjustment of the oscillation frequency is easily achievable.

[0006] One embodiment overcomes all or part of the drawbacks of known solutions and proposes an electronic oscillator comprising a resonator coupled in parallel to at least one active circuit, the resonator comprising two electrodes coupled to separate variable capacitances forming a load capacitance of the electronic oscillator, and a control device configured to independently control the values ​​of the variable capacitances.

[0007] According to a particular embodiment, the control device comprises a digital circuit.

[0008] According to a particular embodiment, each of the variable capacitors comprises a bank of capacitors of different values.

[0009] According to a particular embodiment, each capacitor bank is configured such that the value of the corresponding variable capacitance is at least equal to that of a first capacitor of the capacitor bank.

[0010] According to a particular embodiment, each capacitor bank further comprises at least one second capacitor coupled to a switch controllable by the control device to couple or not couple the second capacitor in parallel to the first capacitor of the capacitor bank.

[0011] According to a particular embodiment, the capacitor banks of the variable capacitances comprise capacitors of identical values ​​from one capacitor bank to another.

[0012] According to a particular embodiment, the control device comprises an adder configured to add a low-order bit of a control signal coded on several bits with a binary number formed from the other bits of the control signal, and the control device is configured to apply an output signal of the adder to at least one control input of a first of the capacitor banks and to apply the binary number to at least one control input of a second of the capacitor banks.

[0013] According to a particular embodiment, the control device comprises a LUT, or a synthesized combinational logic circuit, or a microcontroller.

[0014] According to a particular embodiment, the resonator corresponds to a quartz resonator or to a MEMS resonator.

[0015] According to a particular embodiment, the active component comprises an inverting amplifier.

[0016] According to a particular embodiment, the inverting amplifier comprises at least one MOS transistor.

[0017] According to a particular embodiment, the inverting amplifier further comprises a feedback impedance coupled to the MOS transistor.

[0018] According to a particular embodiment, the variable capacitors are each configured so that their value can vary in a range between 2 pF and 20 pF.

[0019] An RF transmission device is also proposed, comprising at least one electronic oscillator according to a particular embodiment. Brief description of the drawings

[0020] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0021] [Fig.l] represents an electronic oscillator according to a particular embodiment;

[0022] [Fig.2] represents a part of the elements of an electronic oscillator according to a particular embodiment;

[0023] [Fig.3] and [Fig.4] represent equivalent electrical diagrams of a resonator used in an electronic oscillator according to a particular embodiment;

[0024] [Fig.5] represents an equivalent electrical diagram of an electronic oscillator according to a particular embodiment;

[0025] [Fig.6] represents examples of load capacitance values ​​obtained with an electronic oscillator according to a particular embodiment; and

[0026] [Fig.7] represents an RF transmission device comprising an electronic oscillator according to a particular embodiment. Description of the embodiments

[0027] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0028] For the sake of clarity, only the steps and elements useful for understanding the embodiments described have been shown and are detailed. In particular, the production of different elements and circuits, for example the resonator, the adder, the controllable switches, etc., is not detailed. Those skilled in the art will be able to produce in detail the different elements and the different functions of the electronic oscillator described, from the functional description given below.

[0029] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") together, this means that these two elements can be connected or be connected via one or more other elements. Furthermore, throughout this document, the term "coupled" must be understood as meaning "electrically coupled" "trically."

[0030] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures in a normal position of use.

[0031] Unless otherwise specified, the expressions "about", "approximately", "substantially", and "of the order of" mean to within 10%, preferably to within 5%.

[0032] An electronic oscillator 100 according to a particular embodiment is described below in connection with [Fig.l].

[0033] The electronic oscillator 100 comprises a resonator 102. The resonator 102 corresponds for example to a quartz resonator or a piezoelectric MEMS resonator. Such a piezoelectric MEMS resonator comprises for example a layer of doped silicon covered with a layer of piezoelectric material such as AlN.

[0034] The electronic oscillator 100 further comprises an active circuit 104, i.e. an electronic circuit or component providing a gain, coupled in parallel to the resonator 102. According to an exemplary embodiment, the active circuit 104 corresponds to an inverting amplifier comprising at least one MOS transistor 106, for example of the N type, coupled to a current source 108. In the example of [Fig.l], the active circuit 104 is coupled to two electrodes 110, 112 of the resonator 102. In the example of [Fig.l], the gate of the transistor 106 is coupled to the electrode 110 of the resonator 102, and the drain of the transistor 106 is coupled to the electrode 112 of the resonator 102. According to an exemplary embodiment, the transistor 106 may be a GO2 type transistor (i.e. comprising an oxide of thick grid), which has good robustness against electrostatic discharges. Alternatively, transistor 106 may be of type GO1.Alternatively, the active circuit 104 may comprise other types of transistors.

[0035] In the embodiment described, the electronic oscillator 100 further comprises a feedback impedance 114 coupled in parallel to the resonator 102. In the example of [Fig.l], this feedback impedance 114 corresponds to an electrical resistance.

[0036] The electronic oscillator 100 described in this example corresponds to a Pierce oscillator. Alternatively, the electronic oscillator 100 could be different from a Pierce oscillator.

[0037] The electrodes 110, 112 of the resonator 102 are coupled to distinct variable capacitors 116, 118 forming the load capacitor of the electronic oscillator 100. According to a particular embodiment, each of the variable capacitors 116, 118 comprises a bank of capacitors which may or may not have different values. from each other.

[0038] In the example of [Fig.l], each bank of capacitors of the variable capacitors 116, 118 comprises a first capacitor 120, 122 whose value corresponds to the minimum value of each of the variable capacitors 116, 118. In the exemplary embodiment described, this first capacitor 120, 122 of each of the variable capacitors 116, 118 always remains coupled to the resonator 102. In other words, the coupling between the first capacitor 120, 122 of each of the variable capacitors 116, 118 and the resonator 102 is not interrupted during operation of the electronic oscillator 100. In this exemplary embodiment, the value of each of the first capacitors 120, 122 is called “Cfixed”.

[0039] In the example of [Fig. 1], one of the two electrodes of each of the first capacitors 120, 122 is coupled to one of the electrodes 110, 112 of the resonator 102 and the other of the two electrodes of each of the first capacitors 120, 122 is coupled to a reference electrical potential of the electronic oscillator 100, for example the ground of the electronic oscillator 100.

[0040] In the exemplary embodiment described, each bank of capacitors of the variable capacitances 116, 118 comprises, in addition to the first capacitor 120, 122, at least one second capacitor coupled to a controllable switch itself coupled to one of the electrodes 110, 112 of the resonator 102. In the exemplary embodiment described here, each bank of capacitors of the variable capacitances 116, 118 comprises several other capacitors each coupled to a switch which is controllable independently of the others and which is coupled to one of the electrodes 110, 112 of the resonator 102. In the example of [Fig.l], each bank of capacitors of the variable capacitances 116, 118 comprises a second, a third and a fourth capacitor respectively referenced 124, 128, 132 for the variable capacitance 116 and referenced 126, 130, 134 for the variable capacity 118. On the example of [Fig.l], each of the capacitors 124 to 134 comprises a first electrode electrically coupled to the reference electrical potential and a second electrode coupled to a controllable switch respectively referenced 136, 138, 140, 142, 144 and 146. Thus, in each of the capacitor banks of the variable capacitances 116, 118, each of the capacitors 124 to 134 can be coupled in parallel to the first capacitor 120, 122 depending on the open or closed state of the controllable switch 136 to 146 coupled to each of these capacitors 124 to 134.

[0041] In the embodiment described, the capacitors of the banks of variable capacitors 116, 118 have identical values ​​from one bank to another. In the example of [Fig.l], the values ​​of the second, third and fourth capacitors 124 to 134 are respectively equal to C, C / 2 and C / 4. Thus, in this example, each of the variable capacitors 116, 118 can take, depending on the state of the switches com- commands 136 to 146, one of the following values: Cfixed, Cfixed + C / 4, Cfixed + C / 2, Cfixed + 3C / 4, Cfixed + C, Cfixed + 5C / 4, Cfixed + 3C / 2, Cfixed + 7C / 4.

[0042] The values ​​C and Cfixed can here be chosen as a function of the required value of the load capacitance of the electronic oscillator 100. According to an exemplary embodiment, the values ​​C and Cfixed can be chosen such that the values ​​of the variable capacitances 116, 118 can vary in a range between 2 pF and 20 pF, which makes it possible to vary the load capacitance of the oscillator 100 with a value between 1 pF and 10 pF.

[0043] The electronic oscillator 100 further comprises a control device 148 configured to independently control the values ​​of the variable capacitors 116, 118, i.e. such that the values ​​of the variable capacitors 116, 118 can be similar or different from one another. In the exemplary embodiment described, the control device 148 is configured to send control signals to the controllable switches 136 to 146 of each of the variable capacitors 116, 118.

[0044] In the described embodiment, the control device 148 comprises or corresponds to a digital circuit. In the example of [Fig.l], the control device 148 is configured to deliver a first control signal coded on several bits to control the switches 136, 140, 144 of the capacitor bank of the first variable capacitance 116, and to deliver a second control signal coded on several bits to control the switches 138, 142, 146 of the capacitor bank of the second variable capacitance 118.

[0045] Since the variable capacitors 116, 118 are controlled independently of each other, the values ​​of the first and second control signals sent by the control device 148 may be similar when the values ​​of the variable capacitors 116, 118 are intended to be similar, or be different when the values ​​of the variable capacitors 116, 118 are intended to be different from each other.

[0046] Another example of embodiment of the variable capacitors 116, 118 and the control device 148 is shown in [Fig.2].

[0047] In this other example, each of the variable capacitors 116, 118 comprises a bank of capacitors comprising the first capacitor 120, 122 of value “Cfixed” as well as second, third, fourth capacitors 124 to 134 as well as a fifth capacitor 133, 135 having, in this other example, values ​​respectively equal to C, 2C, 4C and 8C. In the example of [Fig. 2], each of the capacitors 124 to 135 comprises a first electrode electrically coupled to the reference electrical potential of the electronic oscillator 100 and a second electrode coupled to a controllable switch 136 to 147 (the fifth capacitors 133, 135 are coupled to the controllable switches 145, 147). Thus, in this example, each of the variable capacitors 116, 118 can take, depending on the state of the controllable switches 136 to 147, a value between Cfixed and Cfixed + 15C, with intermediate values ​​equal to Cfixed + a*C, a being an integer between 1 and 14. The values ​​C and Cfixed are for example chosen such that the values ​​of the variable capacitors 116, 118 can vary in a range between 2 pf and 20 pF.

[0048] In this other example, the control device 148 comprises an adder 150 configured to receive as input an initial control signal coded on several bits (one input for each bit of the initial control signal). In the exemplary embodiment described, the number of bits of the initial control signal is equal to the number of capacitors of each capacitor bank of the variable capacitors 116, 118, i.e. 5 in the example of [Fig. 2]. In this example, the adder 150 is configured to add a low-order bit of the initial control signal with a binary number formed by the other bits of the initial control signal.Furthermore, in the example described, the control device 148 is configured to apply an output signal of the adder 150 to at least one control input (one for each bit in the example described) of the first variable capacitor 116 in order to control the controllable switches of this first variable capacitor 116. In this example, a binary number formed from the bits of the initial control signal other than the least significant bit are applied to at least one control input (one for each bit in the example described) of the second variable capacitor 118 in order to control the controllable switches of this second variable capacitor 118. In the example embodiment described, the number of bits of the signals sent to the input of the variable capacitors 116, 118 is equal to the number of controllable switches of each of the capacitor banks of the variable capacitors 116, 118.

[0049] Thus, in the example of [Fig.2], the adder 150 is configured to perform the addition C = A + B, with B corresponding to the least significant bit of the initial control signal, A corresponding to the binary number formed by the bits at the input of the adder 150 (which also corresponds to the control signal sent to the second variable capacitor 118), and C corresponding to the binary number obtained at the output of the adder 150 (which forms the control signal sent to the first variable capacitor 116). In the example of [Fig.2], the least significant bit of the initial control signal is applied to an input “B0” of the adder 150, the other bits of this initial control signal are applied to inputs “A0”, “A1”, “A2” and “A3” of the adder 150, and the output signal of the adder 150 is delivered to the outputs “C0”, “Cl”, “C2” and “C3” of the adder 150.

[0050] Thus, in the configuration shown in [Fig.2], when the least significant bit of the initial control signal applied to the adder 150 has the value '0', the binary number delivered at the output of the adder 150 is equal to the binary number formed by the other bits of the initial control signal and applied to the input of the adder 150. In this case, the control signals applied to the controllable switches of the capacitor banks of the variable capacitors 116, 118 are identical, which means that the variable capacitors 116, 118 have an identical value. When the bit of the initial control signal applied to the input B of the adder 150 has the value '1', the binary number delivered on the bits of the output C is equal to the sum of a bit '1' with the binary number formed by the other bits of the initial control signal received by the adder 150.In this case, the control signals applied to the controllable switches of the capacitor banks of the variable capacitors 116, 118 are different and the variable capacitors 116, 118 have different values ​​such that C116 = C118 + C, with C116 and C118 corresponding respectively to the values ​​of the variable capacitors 116 and 118. In order to avoid a problem in the event of the capacity of the adder 150 being exceeded (“overflow” situation when all the bits applied at the input are at '1'), the control device 148 may comprise OR gates at the output of the adder 150 in order to set the outputs of the control device 148 to the '1' state in such a case.

[0051] The operation of the electronic oscillator 100 is described in more detail below.

[0052] [Fig. 3] represents an equivalent electrical diagram of the resonator 102, this electrical diagram being applicable for a quartz or piezoelectric MEMS type resonator 102. The resonator 102 can be electrically modeled by a resistor 152, corresponding to the equivalent series resistance of the resonator 102, electrically coupled in series between the first electrode 110 of the resonator 102 and to an inductance 154 itself electrically coupled in series to a first electrode of a first capacitance 156. The resistor 152 is representative of the mechanical losses of the resonator 102 and its value is proportional to the quality factor of the resonator 102 (lower in the case of a piezoelectric MEMS type resonator than for a quartz resonator). The inductance 154 is representative of the elasticity of the resonator 102, and the first capacitance 156 is representative of the mechanical inertia of the resonator 102.A second electrode of the first capacitor 156 is coupled to the second electrode 112 of the resonator 102. A second capacitor 158 is electrically coupled in parallel to the assembly formed by the resistor 152, the inductor 154 and the first capacitor 156. The second capacitor 158 is representative of the parasitic capacitance of the resonator 102 (which is associated with the thickness of the piezoelectric film and its dielectric permittivity in the case of a piezoelectric MEMS type resonator 102).

[0053] [Fig.4] represents the equivalent electrical diagram of the resonator 102 when the latter receives on its electrodes 110, 112 opposite or out-of-phase signals. In this case, the second capacitance 158 previously described in connection with [Fig.3] can be seen as forming two separate capacitances, referenced 160 and 162, each comprising an electrode coupled to a reference electrical potential corresponding for example to the ground of the resonator 102 or to a virtual ground. The value of each of the two capacitances 160, 162 is equal to twice that of the capacitance 158.

[0054] [Fig.5] represents an equivalent electrical diagram of the electronic oscillator 100. In this electrical diagram, in addition to the elements of the resonator 102 previously described in connection with [Fig.4], the active circuit 104 can be electrically modeled by a negative electrical resistance 164 for example of value equal to -Gm / ((2C0+Cl 16).(2CO+C118).2ir.f)2, with Gm corresponding to the transconductance of the transistor 106 (whose value is proportional to the bias current consumed) and f corresponding to the oscillation frequency of the resonator 102. The oscillation frequency fosc of the electronic oscillator 100 is equal to: [Math 1] f = —:■■■■■........... 'ose 27T^Lm.Ceq

[0055] With Lm equal to the value of the inductance 154, and Ceq the value of the equivalent capacitance formed by the different capacitances of the electrical diagram of [Fig.5], and which is such that: [Math 2] _1_ _ _J_ 4. 1 . 1 Ceq Cm C116+2C0 C118+2C0

[0056] With Cm corresponding to the value of the first capacity 156, and C0 corresponding to the value of the second capacity 158.

[0057] The electronic oscillator 100 is in a stable oscillation state when the sum of the values ​​of the electrical resistances 152 and 164 is zero. Since the values ​​of Lm, Cm and CO are not modifiable, the adjustment of the oscillation frequency fosc of the electronic oscillator 100 is carried out by adjusting the values ​​of the variable capacitors 116, 118, which amounts to modifying the value of Ceq, and therefore of fosc.Considering the equivalent electrical diagram of the electronic oscillator 100, the greater the value of the equivalent series resistance 152, the greater the value of the negative electrical resistance 164 must be to compensate for the resistance 152, which results in a greater transconductance Gm (and therefore more current supplied by the transistor 106) or a lower ratio (2C0+C116) / (2CO+C118) obtained by adjusting the values ​​of Cl 16 and Cl 18 (the value C0 not being adjustable because it depends on the physical characteristics of the resonator 102).

[0058] Thus, in order to adjust the oscillation frequency of the electronic oscillator 100 to compensate for possible variations in the resonator 102 (generally + / - 10 ppm), the values ​​of the variable capacitors 116, 118 are chosen by applying the desired control signals to the input of these capacitors, the value CL of the load capacitor obtained being such that CL = (Cl 16 + C118) / 2. Thus, considering that the value of each of the variable capacitors 116, 118 can be adjusted with a step equal to 1 pF, the independent control of the values ​​of the variable capacitors makes it possible to adjust the value CL with a step equal to 0.25 pF.

[0059] [Fig.6] represents the values ​​of the load capacitance CL obtained with variable capacitances 116, 118 as previously described in connection with [Fig.2], with Cfixed = 4 pF and C = 1 pF. The abscissa axis represents the value of the binary word applied to the input of the adder 150 and to the control inputs of the second variable capacitance 118. The values ​​obtained from the load capacitance CL form a monotonic straight line well suited for fine control of the oscillation frequency of the electronic oscillator 100. In the example of [Fig.6], with a 4-bit control signal, 31 different values ​​of the load capacitance CL are possible.

[0060] When the resonator 102 is of the MEMS type, all of the components of the oscillator 100 can be produced within the same chip, for example of the SoC type.

[0061] The electronic oscillator 100 proposes a solution making it possible to increase the resolution of adjustment of the oscillation frequency of the oscillator via an independent adjustment of the value of each of the variable capacitances forming the load capacitance of the electronic oscillator.

[0062] An advantage of the electronic oscillator 100 described above is that the resonator 102 and / or the active circuit 104 and / or the variable capacitors 116, 118 may correspond to existing elements to which the control device 148 is added. For example, an advantage of using a digital control device 148 is that its addition is simpler than modifying or adding analog elements, for example adding capacitors to the capacitor banks of the variable capacitors 116, 118.

[0063] In a particular configuration, the electronic oscillator 100 can have the advantages provided by the use of a Pierce type oscillator structure, that is to say in particular low electrical current consumption, reduced noise, possible operation at high frequency and good robustness with respect to electrostatic discharges.

[0064] The electronic oscillator 100 makes it possible to guarantee a monotonous character of the load capacity values ​​that can be obtained, without complicating its layout or design, and using a reduced number of capacitors or without increasing the number of capacitors used compared to existing solutions.

[0065] The electronic oscillator 100 can be applied to the RF domain and in particular to that of RF SoCs, or even the domain of transceivers and / or that of UWB / NB (narrowband) loT (internet of things) devices. [Fig.7] represents an example of an RF transmission device 1000, corresponding to a UWB transmitter / receiver in this example, comprising an electronic oscillator 100 as previously described.

[0066] In the examples previously described, the electronic oscillator 100 is of the Pierce type. Alternatively, the oscillator 100 may correspond to an oscillator of another type. Furthermore, the active circuit 104 may be different from that previously described.

[0067] The number of capacitors forming the variable capacitances, and therefore also the number of bits used to control the values ​​of the variable capacitances, may be different from those of the examples previously described.

[0068] Control devices 148 different from that previously described, i.e. comprising one or more electronic components or circuits other than an adder, may be used to perform the same functions as those performed by the example control device 148 previously described. For example, the control device may comprise a LUT (Look Up Table), or a synthesized combinational logic circuit, or a microcontroller.

[0069] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will occur to those skilled in the art.

[0070] Finally, the practical implementation of the embodiments and variants described is within the reach of those skilled in the art from the functional indications given above.

Claims

Claims

1. An electronic oscillator (100) comprising a resonator (102) coupled in parallel to at least one active circuit (104), the resonator (102) comprising two electrodes (110, 112) coupled to separate variable capacitors (116, 118) forming a load capacitor of the electronic oscillator (100), and a controller (148) configured to independently control the values ​​of the variable capacitors (116, 118).

2. The electronic oscillator (100) of claim 1, wherein the control device (148) comprises a digital circuit.

3. Electronic oscillator (100) according to one of the preceding claims, in which each of the variable capacitors (116, 118) comprises a bank of capacitors (120 - 135) of different values.

4. An electronic oscillator (100) according to claim 3, wherein each capacitor bank (120-135) is configured such that the value of the corresponding variable capacitance (116, 118) is at least equal to that of a first capacitor (120, 122) of the capacitor bank (120-135).

5. Electronic oscillator (100) according to claim 4, wherein each capacitor bank (120 - 135) further comprises at least one second capacitor (124 - 135) coupled to a switch controllable (136 - 147) by the control device (148) to couple or not the second capacitor (124 - 135) in parallel with the first capacitor (120, 122) of the capacitor bank (120 - 135).

6. Electronic oscillator (100) according to one of claims 3 to 5, in which the capacitor banks (120 - 135) of the variable capacitors (116, 118) comprise capacitors (120 - 135) of identical values ​​from one capacitor bank (120 - 135) to the other.

7. Electronic oscillator (100) according to claim 2 and one of claims 3 to 6, wherein the control device (148) comprises an adder (150) configured to add a least significant bit of a control signal coded on several bits with a binary number formed from the other bits of the control signal, and wherein the control device (148) is configured to apply an output signal of the adder (150) to at least one control input of a first of the capacitor banks (120, 124, 128, 132, 133) and to apply the binary number to at least one input controlling a second of the capacitor banks (122, 126, 130, 134, 135).

8. Electronic oscillator (100) according to one of claims 1 to 6, in which the control device (148) comprises a LUT, or a synthesized combinational logic circuit, or a microcontroller.

9. Electronic oscillator (100) according to one of the preceding claims, in which the resonator (102) corresponds to a quartz resonator or a MEMS resonator.

10. Electronic oscillator (100) according to one of the preceding claims, in which the active component (104) comprises an inverting amplifier.

11. Electronic oscillator (100) according to claim 10, wherein the inverting amplifier comprises at least one MOS transistor (106).

12. The electronic oscillator (100) of claim 11, wherein the inverting amplifier further comprises a feedback impedance (114) coupled to the MOS transistor (106).

13. Electronic oscillator (100) according to one of the preceding claims, wherein the variable capacitors (116, 118) are each configured so that their value can vary in a range between 2 pF and 20 pF.

14. RF transmission device (1000), comprising at least one electronic oscillator (100) according to one of the preceding claims.

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