Designing and constructing wireless communication apparatus to reduce current ringing

Abstract

In an example, a method of designing wireless communication apparatus is provided. The wireless communication apparatus comprises at least one power supply, at least one wireless transceiver, and at least one power cable between the at least one power supply and the at least one wireless transceiver. The method comprises modelling the wireless communication apparatus as a resistor inductor capacitor (RLC) network, and selecting one or more components for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold. The method also comprises applying the selected one or more components to a design of the wireless communication apparatus.

Description

[0001] DESIGNING AND CONSTRUCTING WIRELESS COMMUNICATION

[0002] APPARATUS TO REDUCE CURRENT RINGING

[0003] Technical Field

[0004] Examples of this disclosure relate to designing and constructing wireless communication apparatus, for example to maintain a step response of a resistor inductor capacitor (RLC) network modelling the wireless communication apparatus within an overshoot threshold and / or an undershoot threshold.

[0005] Background

[0006] The power supply system for fifth generation (5G) mobile networks requires a high level of stability and reliability to be able to support the use cases. Current ringing issues have been observed in several radio products, for example ringing between a power supply unit (PSU) and apparatus implementing a remote radio unit (RRU), and ringing between a power cable and apparatus implementing a RRU. These current ringing issues should be avoided since they may affect the performance of the radio or even cause a radio system shut-down.

[0007] The current ringing issues are caused by the interaction of the radio DC / DC interface (i.e. the physical connection point of the RRU to the power cable) and the power cable or Power Supply Unit (PSU) connected to the radio, which means even though the radio DC / DC interface, the AC / DC PSU, and the power cable fulfill all their stand-alone requirements, the ringing issue could still occur. Since the current ringing issue cannot be evaluated until the final system level test and verification are implemented, when the issue occurs the opportunity to fix the issue is limited, and it may not be possible to update the design of the radio DC / DC interface significantly.

[0008] Summary

[0009] Some examples of this disclosure may mitigate one or more of the above-identified problems. For example, examples of this disclosure may provide a design or construction of wireless communication apparatus including a step current damper for a radio power interface to manage the overshoot and undershoot of step current ringing at the radio power interface. Proposed examples may be effective and easy to implement. One aspect of the present disclosure provides a method of designing wireless communication apparatus. The wireless communication apparatus comprises at least one power supply, at least one wireless transceiver, and at least one power cable between the at least one power supply and the at least one wireless transceiver. The method comprises modelling the wireless communication apparatus as a resistor inductor capacitor (RLC) network, and selecting one or more components for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold. The method also comprises applying the selected one or more components to a design of the wireless communication apparatus.

[0010] Another aspect of the present disclosure provides a method of constructing wireless communication apparatus. The wireless communication apparatus comprises at least one power supply, at least one wireless transceiver, and at least one power cable between the at least one power supply and the at least one wireless transceiver. The method comprises designing the wireless communication apparatus by modelling the wireless communication apparatus as a resistor inductor capacitor (RLC) network; selecting one or more components for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold; and applying the selected one or more components to a design of the wireless communication apparatus. The method of constructing the wireless communication apparatus includes constructing the wireless communication apparatus according to the design of the wireless communication apparatus.

[0011] Another aspect of the present disclosure provides wireless communication apparatus designed or constructed according to one of the above aspects.

[0012] Existing methods to solve the current ringing issue involve trial and error approaches. Solutions include using a longer power cable and adding more capacitance, for example by adding more hold upo capacitors or using larger hold up capacitors. However, since the root cause of the current ringing issue was not clear, these solutions are not optimized, in that they may solve the current ringing issue but may cause other issues. For example, using a longer power cable reduces the overshoot and undershoot of the step current ringing because it increases the resistance of power transmission line, but it also leads to a higher power loss and a higher cost. Furthermore, the trial and error approaches may consume significant time and resources due to the large number of circuit parameters that may be modified. Brief Description of the Drawings

[0013] For a better understanding of the embodiments of the present disclosure, and to show how it may be put into effect, reference will now be made, by way of example only, to the accompanying figures, in which:

[0014] Figure 1 illustrates an example of a wireless communication apparatus;

[0015] Figure 2 is a flow chart of an example of a method of designing wireless communication apparatus;

[0016] Figure 3 illustrates an example of a circuit that represents a wireless communication apparatus;

[0017] Figure 4 illustrates an example of a RLC model of a wireless communication apparatus;

[0018] Figure 5 shows an example of the relationship between overshoot and damping ratio for a 2nd order system;

[0019] Figure 6 illustrates an example of a model of a wireless communication apparatus;

[0020] Figure 7 illustrates another example of a model of a wireless communication apparatus;

[0021] Figure 8 illustrates another example of a model of a wireless communication apparatus;

[0022] Figure 9 illustrates another example of a model of a wireless communication apparatus; and

[0023] Figure 10 is a flow chart of an example of a method of constructing wireless communication apparatus.

[0024] Detailed Description

[0025] The following sets forth specific details, such as particular embodiments or examples for purposes of explanation and not limitation. It will be appreciated by one skilled in the art that other examples may be employed apart from these specific details. In some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g. analog and / or discrete logic gates interconnected to perform a specialized function, Application Specific Integrated Circuits (ASICs), Programmable Logic Arrays (PLAs), etc.) and / or using software programs and data in conjunction with one or more digital microprocessors or general purpose computers. Nodes that communicate using the air interface also have suitable radio communications circuitry. Moreover, where appropriate parts of the technology can additionally be considered to be embodied entirely within any form of computer-readable memory, such as solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

[0026] Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g. digital or analogue) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and / or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

[0027] The object of examples of this disclosure is for example to provide a damper circuit at the radio power interface to limit the overshoot and / or undershoot of a step current response efficiently and effectively. In an example, a system model based on the 2nd order system in the classical control theory is proposed to accurately describe the relationship between the current ringing overshoot / undershoot and the system damping ratio. The system damping ratio may be for example a function of one or more parameters including AC / DC PSU output impedance, cable length, radio DC / DC electromagnetic interference (EMI) filter resistance and indictance, hold-up capacitance, and radio input power. Then, for a given requirement for the overshoot / undershoot of the current ringing at the radio power interface, its corresponding damping ratio of the 2nd order system model may be defined. The damping ratio obtained in the second part may then be achieved in wireless communication apparatus by selecting one or more components (e.g. a damper circuit) using the function referred to above.

[0028] Figure 1 illustrates an example of a wireless communication apparatus 100. The apparatus 100 includes a power supply (PSU) 102 and a wireless transceiver 104. The radio apparatus 104 may for example comprise apparatus for a radio unit, remote radio unit (RRU), remote radio head (RRH), base station or any other apparatus that includes a wireless transceiver. A power cable 106 connects the power supply 104 to the radio apparatus 104, and a radio power interface 108 (e.g. a radio DC / DC interface) is present, such as for example a -48V radio DC / DC interface.

[0029] When the transceiver 104 has a high load step current (for example due to a switch between transmission mode and reception mode of the transceiver 104), its step current response may cause a ringing current at the input of radio with a large overshoot and / or undershoot. The large overshoot may trigger over current protection of the transceiver or radio unit, and the large undershoot may trigger polarity protection of the transceiver or radio unit. Both protections can cause a shut down of the radio.

[0030] Figure 2 is a flow chart of an example of a method 200 of designing wireless communication apparatus. The method 200 may in some examples be a computer-implemented method. The wireless communication apparatus comprises at least one power supply, at least one wireless transceiver, and at least one power cable between the at least one power supply and the at least one wireless transceiver. Thus, the wireless communication apparatus may be for example the wireless communication apparatus 100 of Figure 1 , with at least one power supply 102, at least one wireless transceiver 104, and at least one power cable 106.

[0031] The method 200 comprises, in step 202, modelling the wireless communication apparatus as a resistor inductor capacitor (RLC) network. Further details and examples are provided below. The method 200 also includes, in step 204, selecting one or more components for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold. Step 206 of the method 200 comprises applying the selected one or more components to a design of the wireless communication apparatus. The step response of the RLC network may be for example a response of the RLC network to an input voltage or current step from a first voltage to a second voltage, for example due to a change of current demand from the wireless transceiver 104, for example when switching from a transmission mode to a reception mode or vice versa. The first voltage may be for example a reference voltage or ground.

[0032] Figure 3 illustrates an example of a circuit 300 that represents a wireless communication apparatus, such as for example the wireless communication apparatus 100 of Figure 1 . The model may be for example a mathematical model or a model that is suitable for simulation on data processing apparatus. The model 300 includes a power supply 302 and a wireless transceiver 304. A power cable 306 connects the power supply 302 and the wireless transceiver 304.

[0033] The power supply 302 is modelled as an ideal -48V DC voltage source 308 in series with a surge protection device (SPD) 310, which is modelled as a series resistance 312 and inductance 314. The power cable 306 is modelled as two parallel conductors, one of which has a series resistance 316 and inductance 318. The resistance and inductance of these may for example represent the length of the power cable being modelled. The wireless transceiver 304 is modelled as a device 320 that represents a SPD, an electromagnetic compatibility (EMC) filter and a hot swap (HS) protection device (although one or more of these may be omitted or not modelled in other examples), and is modelled as a series resistance 322 and inductance 324. A DC / DC converter 326 is modelled in series with the device 320. This is modeled as a current source 328 and input impedance, and the input impedance in small-signal analysis can be further simplified as a negative resistor 330 (which is output power related). The apparent negative input impedance of the DC / DC converter 326 may change with the load it supplies. For example, to draw constant power, the current may increase with a decrease in input voltage, thus resulting in an apparent negative resistance. The DC / DC converter 326 may for example maintain a regulated output within strict limits to satisfy critical requirements of the internal loads for their proper function, while operating in the presence of external input voltage variations and internal load changes.

[0034] The wireless transceiver 304 also includes hold-up capacitors 332 in parallel with the DC / DC converter 326, and are modelled as a series resistance 334 and capacitance 336.

[0035] The model 300 in Figure 3 can be simplified as a RLC model, an example of which is shown in Figure 4. The RLC model 400 of Figure 4 includes a voltage input 308 (vin) applied across a series connected inductance 404 (L), resistance 406 (RL), resistance 408 (Rc) and capacitance 410 (C). A resistance 412 (R is connected in parallel with the resistance 408 and capacitance 410. The resistance R of resistance 412 may in some examples depend on load and input voltage, represented by 70.

[0036] In some examples, the inductances and resistances of the power supply SPD 310, power cable 306 and wireless transceiver 304 are represented by the single inductance 404 with inductance L and single resistor 406 with resistance R . The RLC circuit in classical control theory can be described by a 2nd order model.

[0037] Transfer functions of the 2nd order model can be derived by using classical control theory. For example, the input voltage to output voltage transfer function is written as: where:

[0038] According to the classical control theory, for a typical 2nd order system G(s): where to0is natural frequency, is damping ratio. Its overshoot and damping ratio relationship are shown in Figure 5, which shows an example of the relationship between overshoot and damping ratio for a 2nd order system. According to Figure 5, for a given overshoot, a damping ratio can be defined by using the 2nd order system model. From the RLC model 400 in Figure 4 and equation (1 ) above, damping ratio is related to the L, C, and R values, and these L, C, and R values are determined by the circuit parameters of the radio power system (see Figure 2).

[0039] In some examples, to further simplify the design of the RLC network, the DC / DC converter may be ignored (e.g. resistor 412 in Figure 4 is infinite) and the damping ratio according to equation Error! Reference source not found, can be re-written as:

[0040] Therefore, in some examples, if the current ringing overshoot is too high (i.e. damping ratio is too low), then one or more components of the RLC network may be selected in step 204 of the method 200 to increase the damping ratio by increasing Rc, RL, and / or C, or reducing L. Increasing Rc may be achieved in a wireless communication apparatus design (and hence for example by increasing the equivalent series resistance (ESR) of hold up capacitors. Increasing C may be achieved for example by adding more hold-up capacitors. Increasing RL may be achieved for example by adding resistors in series with the EMC filter and hot-swap circuit. Reducing L may be achieved for example by using a lower inductance SPD, using lower inductance cable, etc.

[0041] Referring back to the method 200 of Figure 2, in some examples, applying the selected one or more components to the design of the wireless communication apparatus in step 206 comprises applying the selected one or more components to the design of the wireless communication apparatus such that the RLC network with the one or more components applied models the design of the wireless communication apparatus. That is, for example, components are applied (e.g. components added and / or component values adjusted) to the design of the wireless communication apparatus, such that its step response is the same as or similar to the step response of the RLC network after the components are selected in step 204.

[0042] In some examples, selecting one or more components for the RLC network in step 204 may comprise selecting one or more values of the one or more components in the RLC network. That is, for example, values of resistance(s), capacitance(s) and / or inductance(s) may be selected for any of the components in the RLC network 400. Then, for example, applying the selected one or more components to the design of the wireless communication apparatus in step 206 may comprise selecting one or more values of components in the wireless communication apparatus that correspond to the one or more components in the RLC network. For example, if the resistance 408 or capacitance 410 is adjusted in the selecting step 204, the capacitance of the hold up capacitors 332 or the equivalent series resistance (ESR) of the hold up capacitors 332 may be selected or adjusted accordingly for the design of the wireless communication apparatus.

[0043] Thus, in some examples, selecting one or more values of the one or more components in the RLC network in step 204 may comprise selecting or adjusting a resistance, inductance and / or capacitance of the one or more components in the RLC network. Selecting or adjusting the resistance of the one or more components in the RLC network may in some examples comprise selecting a negative resistance. In particular, a negative resistance may be implemented for the resistance 412 in the RLC network 400 that represents the DC / DC converter 326, for example as suggested above.

[0044] Selecting one or more components for the RLC network in step 204 of the method 200 may in some examples additionally or alternatively comprise selecting a capacitance of one or more hold up capacitors in one or more of the at least one wireless transceiver, selecting an impedance of the at least one power cable, and / or selecting one or more components for the RLC network comprises selecting an impedance of one or more of a surge protection device, a hot swap protection device and an electromagnetic compatibility (EMC) filter in one or more of the at least one wireless transceiver. Further, selecting one or more components for the RLC network qin step 204 may in some examples additionally or alternatively comprise selecting an impedance of one or more of a surge protection device and a distribution network in one or more of the at least one power supply, and / or selecting a shape of an impedance of one or more DC / DC converters in one or more of the at least one wireless transceiver.

[0045] In some examples, selecting one or more components for the RLC network in step 204 of the method 200 may comprise adding additional components to the RLC network. In such examples, applying the selected one or more components to the design of the wireless communication apparatus in step 206 may comprise adding one or more additional components to the wireless communication apparatus that correspond to the one or more additional components in the RLC network. In some examples, the same components are added to the design of the wireless communication apparatus as are applied to the RLC network model, e.g. the same resistor(s), capacitor(s) and / or inductor(s), and connected to the same components (e.g. a component in series or parallel with the resistor 408 and capacitor 410 in the RLC network model 400 can be included in series or parallel with hold up capacitors 332 shown in Figure 3).

[0046] Adding additional components to the RLC network may comprise for example adding one or more additional resistances, inductances and / or capacitances to the RLC network. For example, adding additional components to the RLC network may comprise adding at least one impedance in series and / or in parallel with one or more hold up capacitors in one or more of the at least one wireless transceiver, or adding at least one impedance in series with one or more of the at least one power cable (e.g. in one or more of the at least one wireless transceiver, for example between the power cable 306 and device 320 shown in Figure 3).

[0047] Figure 6 illustrates an example of a model of a wireless communication apparatus 600. Components that are similar to those in the apparatus 300 of Figure 3 are given the same reference numerals. The model of the apparatus 600 is similar to that of the apparatus 300 shown in Figure 3, except that a resistance 602 (Rdamp) has been added to the transceiver apparatus 304 in series between the power cable 306 and the device 320, for example following a similar component being added to the model of the RLC network 400 shown in Figure 4. Thus, in the design of the wireless communication apparatus, a resistance with a value Rdamp may be added in series with the power cable, e.g. between the power cable and one or more of the SPD, HS protection device, and / or EMC.

[0048] Figure 7 illustrates another example of a model of a wireless communication apparatus 700. Components that are similar to those in the apparatus 300 of Figure 3 are given the same reference numerals. The model of the apparatus 700 is similar to that of the apparatus 300 shown in Figure 3, except that a parallel combination of a resistance 702 (Rdamp) and inductance 704 (Ldamp) has been added to the transceiver apparatus 304 in series between the power cable 306 and the device 320, for example following a similar components being added to the model of the RLC network 400 shown in Figure 4. Thus, in the design of the wireless communication apparatus, a parallel combination of a resistance with a value Rdamp and inductance with a value Ldamp may be added in series with the power cable, e.g. between the power cable and one or more of the SPD, HS protection device, and / or EMC.

[0049] Figure 8 illustrates an example of a model of a wireless communication apparatus 800. Components that are similar to those in the apparatus 300 of Figure 3 are given the same reference numerals. The model of the apparatus 800 is similar to that of the apparatus 300 shown in Figure 3, except that a resistance 802 (Rdamp) has been added to the transceiver apparatus 304 in series with hold up capacitors 332, for example following a similar component being added to the model of the RLC network 400 shown in Figure 4. Thus, in the design of the wireless communication apparatus, a resistance with a value Rdamp may be added in series with the hold up capacitors.

[0050] Figure 9 illustrates an example of a model of a wireless communication apparatus 900. Components that are similar to those in the apparatus 300 of Figure 3 are given the same reference numerals. The model of the apparatus 900 is similar to that of the apparatus 300 shown in Figure 3, except that a series combination of a resistance 802 (Rdamp) and capacitance 904 (Cdamp) has been added to the transceiver apparatus 304 in parallel with hold up capacitors 332, for example following similar components being added to the model of the RLC network 400 shown in Figure 4. Thus, in the design of the wireless communication apparatus, a series combination of a resistance with a value Rdamp and a capacitance with value Cdamp may be added in series with the hold up capacitors.

[0051] The examples shown in Figures 6-9 are merely illustrative examples, and may in other examples be used in any combination, and / or any other components may be added or adjusted to achieve maintaining a step response of the RLC network (and thus the design of the wireless communication apparatus) within an overshoot threshold and / or an undershoot threshold. Other possible examples may include: active ESR control of the hold up capacitors, an active ripple injector circuit in parallel with the hold-up capacitors, feedforward control of the DC / DC converter, and / or using an open-loop DC / DC converter instead of a closed-loop DC / DC converter.

[0052] In this disclosure, the overshoot threshold referred to herein comprises a voltage overshoot threshold or a current overshoot threshold. Similarly, the undershoot threshold referred to herein comprises a voltage undershoot threshold or a current undershoot threshold.

[0053] In general examples, the RLC network referred to herein may comprise at least a first inductance (e.g. inductance 404), first resistance (e.g. resistance 406 and / or resistance 408) and a first capacitance (e.g. capacitance 410) connected in series. In some examples, the first resistance may be a negative resistance. The step response of the RLC network may comprise for example a step response across the first resistance and the first capacitance.

[0054] The RLC network may in some examples comprises a second resistance (e.g. resistance 406 or 408) connected in series with the first inductance. Thus, the first inductance and second resistance may model one or more of the following:

[0055] • one or more of a surge protection device, a hot swap protection device and an electromagnetic compatibility (EMC) filter in one or more of the at least one wireless transceiver;

[0056] • one or more of a surge protection device and an electromagnetic compatibility (EMC) filter in one or more of the at least one power supply;

[0057] • an inductance and / or resistance of one or more of the at least one power cable; and

[0058] • an inductance and / or resistance of one or more of a surge protection device and a distribution network in one or more of the at least one power supply.

[0059] The first resistance (e.g. resistance 408) and the first capacitance (e.g. capacitance 410) may for example model one or more hold up capacitors in one or more of the at least one wireless transceiver. The RLC network may also comprise a third resistance (e.g. resistance 412) connected in parallel with the first resistance and the first capacitance. The third resistance may model one or more DC / DC converters in one or more of the at least one wireless transceiver. The third resistance may be a negative resistance in some examples. Figure 10 is a flow chart of an example of a method 1000 of constructing wireless communication apparatus. The wireless communication apparatus comprises at least one power supply, at least one wireless transceiver, and at least one power cable between the at least one power supply and the at least one wireless transceiver. Thus, the wireless communication apparatus may be for example the wireless communication apparatus 100 of Figure 1 , with at least one power supply 102, at least one wireless transceiver 104, and at least one power cable 106.

[0060] The method 1000 comprises designing the wireless communication apparatus by, in step 1002, modelling the wireless communication apparatus as a resistor inductor capacitor (RLC) network; in step 1004, selecting one or more components for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold; and in step 1006, applying the selected one or more components to a design of the wireless communication apparatus. The steps 1002-1006 may in some examples be similar to steps 202-206 of the method 200 of Figure 2 described above, or any variants thereof.

[0061] The method 1000 of constructing the wireless communication apparatus also includes, in step 1008, constructing the wireless communication apparatus according to the design of the wireless communication apparatus. Thus the resulting wireless communication apparatus may maintain a step response (e.g. across input terminals of the wireless transceiver, across hold up capacitors, at an input terminal of the wireless transceiver, and / or at any other point(s) in the wireless communication apparatus) within an overshoot threshold and / or an undershoot threshold. Thus, step current ringing may be reduced or eliminated in examples of this disclosure.

[0062] It should be noted that the above-mentioned examples illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative examples without departing from the scope of the appended statements. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim, “a” or “an” does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the statements below. Where the terms, “first”, “second” etc. are used they are to be understood merely as labels for the convenient identification of a particular feature. In particular, they are not to be interpreted as describing the first or the second feature of a plurality of such features (i.e. , the first or second of such features to occur in time or space) unless explicitly stated otherwise. Steps in the methods disclosed herein may be carried out in any order unless expressly otherwise stated. Any reference signs in the statements shall not be construed so as to limit their scope.

Claims

Claims1 . A method (200) of designing wireless communication apparatus (600, 700, 800, 900), wherein the wireless communication apparatus comprises at least one power supply (302), at least one wireless transceiver (304), and at least one power cable (306) between the at least one power supply and the at least one wireless transceiver, the method comprising: modelling (202) the wireless communication apparatus as a resistor inductor capacitor, RLC, network (400); selecting (204) one or more components (602, 702, 704, 802, 902, 904) for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold; and applying (206) the selected one or more components to a design of the wireless communication apparatus.

2. The method of claim 1 , wherein applying (206) the selected one or more (602, 702, 704, 802, 902, 904) components to the design of the wireless communication apparatus (600, 700, 800, 900) comprises applying the selected one or more components to the design of the wireless communication apparatus such that the RLC network (400) with the one or more components applied models the design of the wireless communication apparatus.

3. The method of claim 1 or 2, wherein selecting one or more components (602, 702, 704, 802, 902, 904) for the RLC network (400) comprises selecting one or more values of the one or more components in the RLC network.

4. The method of claim 3, wherein applying the selected one or more components to the design of the wireless communication apparatus () comprises selecting one or more values of components in the wireless communication apparatus that correspond to the one or more components in the RLC network (400).

5. The method of claim 3 or 4, wherein selecting one or more values of the one or more components in the RLC network (400) comprises selecting or adjusting a resistance, inductance and / or capacitance of the one or more components in the RLC network.

6. The method of claim 5, wherein selecting or adjusting the resistance of the one or more components in the RLC network (400) comprises selecting a negative resistance.

7. The method of any of claims 3 to 6, wherein selecting one or more components (602, 702, 704, 802, 902, 904) for the RLC network (400) comprises selecting a capacitance of one or more hold up capacitors in one or more of the at least one wireless transceiver (304).

8. The method of any of claims 3 to 7, wherein selecting one or more components for the RLC network (400) comprises selecting an impedance of the at least one power cable (306).

9. The method of any of claims 3 to 8, wherein selecting one or more components for the RLC network (400) comprises selecting an impedance of one or more of a surge protection device, a hot swap protection device and an electromagnetic compatibility, EMC, filter in one or more of the at least one wireless transceiver (304).

10. The method of any of claims 3 to 9, wherein selecting one or more components for the RLC network (400) comprises selecting an impedance of one or more of a surge protection device and a distribution network in one or more of the at least one power supply (306).11 . The method of any of claims 3 to 10, wherein selecting one or more components for the RLC network (400) comprises selecting a shape of an impedance (412) of one or more DC / DC converters (326) in one or more of the at least one wireless transceiver.

12. The method of claim 1 or 2, wherein selecting one or more components (602, 702, 704, 802, 902, 904) for the RLC network (400) comprises adding additional components to the RLC network.

13. The method of claim 12, wherein applying (206) the selected one or more components (602, 702, 704, 802, 902, 904) to the design of the wireless communication apparatus (600, 700, 800, 900) comprises adding one or more additional components to the wireless communication apparatus that correspond to the one or more additional components in the RLC network (400).

14. The method of claim 12 or 13, wherein adding additional components to the RLC network (400) comprises adding one or more additional resistances, inductances and / or capacitances to the RLC network.

15. The method of any of claims 12 to 14, wherein adding additional components to the RLC network (400) comprises adding at least one impedance (802, 902) in series and / or in parallel with one or more hold up capacitors (332) in one or more of the at least one wireless transceiver (304).

16. The method of any of claims 12 to 15, wherein adding additional components to the RLC network (400) comprises adding at least one impedance (702, 704) in series with one or more of the at least one power cable (306).

17. The method of claim 16, wherein the at least one impedance (702, 704) in series with one or more of the at least one power cable (306) is added in one or more of the at least one wireless transceiver (304).

18. The method of any of claims 1 to 17, wherein : the overshoot threshold comprises a voltage overshoot threshold or a current overshoot threshold; and / or the undershoot threshold comprises a voltage undershoot threshold or a current undershoot threshold.

19. The method of any of claims 1 to 18, wherein the step response of the RLC network (400) comprises a response of the RLC network to an input voltage step from a first voltage to a second voltage.

20. The method of claim 19, wherein the first voltage comprises a reference voltage or ground.21 . The method of any of claims 1 to 20, wherein the RLC network (400) comprises at least a first inductance (404), first resistance (406, 408) and a first capacitance (410) connected in series.

22. The method of claim 21 , wherein the first resistance comprises a negative resistance.

23. The method of claim 21 or 22, wherein the step response of the RLC network (400) comprises a step response across the first resistance (406, 408) and the first capacitance (410).

24. The method of any of claims 21 to 23, wherein the RLC network (400) comprises a second resistance (406) connected in series with the first inductance (404).

25. The method of claim 24, wherein the first inductance (404) and second resistance (406) model one or more of:one or more of a surge protection device, a hot swap protection device and an electromagnetic compatibility, EMC, filter in one or more of the at least one wireless transceiver (304); one or more of a surge protection device and an electromagnetic compatibility, EMC. filter in one or more of the at least one power supply (302); an inductance and / or resistance of one or more of the at least one power cable (306); and an inductance and / or resistance of one or more of a surge protection device and a distribution network in one or more of the at least one power supply.

26. The method of any of claims 21 to 25, wherein the first resistance (408) and the first capacitance (410) model one or more hold up capacitors (332) in one or more of the at least one wireless transceiver (304).

27. The method of any of claims 21 to 26, wherein the RLC network (400) comprises a third resistance (412) connected in parallel with the first resistance and the first capacitance.

28. The method of claim 27, wherein the third resistance (412) models one or more DC / DC converters (326) in one or more of the at least one wireless transceiver (304).

29. The method of claim 27 or 28, wherein the third resistance (412) is a negative resistance.

30. A method (1000) of constructing wireless communication apparatus (600, 700, 800, 900), wherein the wireless communication apparatus comprises at least one power supply (302), at least one wireless transceiver (304), and at least one power cable (306) between the at least one power supply and the at least one wireless transceiver, the method comprising: designing the wireless communication apparatus by: modelling (1002) the wireless communication apparatus as a resistor inductor capacitor, RLC, network (400); selecting (1004) one or more components (602, 702, 704, 802, 902, 904) for the RLC network that when applied to the RLC network maintain a step response of the RLC network within an overshoot threshold and / or an undershoot threshold; and applying (1006) the selected one or more components to a design of the wireless communication apparatus; and wherein the method of constructing the wireless communication apparatusincludes: constructing (1008) the wireless communication apparatus according to the design of the wireless communication apparatus. 31 . The method of claim 30, wherein designing the wireless communication apparatus(600, 700, 800, 900) is performed according to the method (200) of any of claims 2 to 29.

32. A wireless communication apparatus (600, 700, 800, 900) designed according to the method (200) of any of claims 1 to 29 or constructed according to the method (1000) of claim 30 or 31.

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